Byleth

"How lovely...it would be for this moment to last forever..."

- Rhea talking to Byleth

Byleth is a playable character and the main protagonist in Fire Emblem: Three Houses. As an Avatar, their name, gender, and birthday are customizable by the player.

They possess the mysterious Crest of Flames and can wield the Sword of the Creator.

Profile
Born to Jeralt and his wife on the 20th of the Horsebow Moon 1159, Byleth lost their mother shortly after their birth. She was buried at Garreg Mach Monastery. Some time after her death, Jeralt left the Knights of Seiros, taking his newborn child with him to travel Fódlan, becoming a mercenary in the process and starting his own mercenary company.

The reason for Jeralt's departure began with the circumstances behind Byleth's birth. Byleth's mother was the twelfth created vessel intended to host the spirit of Sothis through her Crest of Flames. Like her predecessors, she too was unable to fully merge with Sothis. The vessel eventually fell in love with Jeralt, who had received Seiros's crest when Rhea, Seiros's current alias, gave him her blood after he took a mortal wound in her stead. The union of the vessel and inheritor of Seiros' crest resulted in the birth of Byleth. However, both the mother and child were too feeble, the latter especially having no heartbeat. Dying herself, the mother pleaded to Rhea to transfer the Crest of Flames into her newborn. The transplant was a success and the child was revived, but at the cost of the mother dying. Jeralt, shocked by his wife's death, had a doctor examine his newborn to discover that they had a pulse, but no heartbeat.

Jeralt's existing suspicions of Rhea grew after this event, especially with Byleth's unusual behavior, neither crying nor laughing as a baby. By Wyvern Moon 1159, Jeralt sought a way to leave Garreg Monastery and the Church of Seiros by any means. Starting a blaze, he used the event to claim that his child had perished in the blaze on the 7th day of the month. Supposedly heartbroken by the deaths of his wife and child, he left the Monastery and secretly took Byleth with him. He formed his own band of mercenaries mainly to mask his movement throughout Fódlan so spies of the Church of Seiros could not easily track him or his child.

During Byleth's childhood, Jeralt shared little information about the world, the Church of Seiros and especially his past. Their true birthdate and age was forgotten, with Jeralt claiming they were born after the fire to a different woman who supposedly died of illness. Jeralt trained Byleth in combat, eventually joining his band of mercenaries and gaining a fearsome reputation for their unflinching courage in battle. They would soon be known as the "Ashen Demon" as a result.

In recent times, Byleth has been having dreams of a young green-haired girl, however when they inquire with Jeralt, he does not know anyone by the same description. Jeralt reminds Byleth that their next job will bring them to the Holy Kingdom of Faerghus, but a sudden uproar occurs when three students from the Officers Academy, Edelgard, Dimitri, and Claude approach the two, asking for their assistance with some bandits trying to kill and plunder the trio. With Byleth and Jeralt's help, most of the bandits are dispatched, save for their leader Kostas who attempts to attack Edelgard, forcing Byleth to step in between her and his Axe. Just as Byleth is about to be struck, time freezes and Byleth encounters the green-haired girl once more who chastises them for being reckless. Introducing herself as Sothis, a name she just recalled, she and Byleth realize that they can rewind time so they can prevent Byleth's impending demise. The flow of time reverses and Byleth is able to not only push Edelgard out of the way, but also disarm Kostas, quelling the remaining bandits.

Reinforcements arrive from the Knights of Seiros shortly afterwards and one of its members, Alois, recognizes Jeralt. He invites the two to visit Garreg Mach Monastery and they comply. Before departing, Byleth converses with the trio from earlier, each impressed by their skill. They extend invitations to join the service of their respective kingdoms and Byleth expresses interest in one of them. Given the journey ahead, the trio get to know Byleth in order to sway them over to their side.

The Archbishop of the Church of Seiros, Rhea thanks Byleth for saving the students. Impressed by their skill, she hires them to become a professor of the students as a vacancy had just opened up. Despite Jeralt's wariness, Byleth accepts the position after Jeralt himself is asked to rejoin the Knights of Seiros. One of Byleth's fellow professors Hanneman asks Byleth to use his special device to determine if they hold a crest. To both their astonishment, not only does Byleth have a crest, but also it is a crest never seen before.

Academy Phase
After taking time to talk to the three house leaders and learning more about the students in each of their houses, Byleth chooses one of them to serve as professor. This choice does not change much of the Academy Phase's storyline as the events of this phase are shared.

As part of their duties, Officer Academy students are given tasks each month by the Church. The first month, the Great Tree Moon has no formal mission for the students, just an annual house mock battle competition between the three houses. Through Byleth's leadership, their class emerges victorious. The Harpstring Moon marks the first formal mission that Byleth's class receives. Tasked with dispatching bandits at Zanado, the battle serves as the first real taste of combat to the students. This battle would mark the beginning of a long string of events behind a greater conspiracy.

The Garland Moon has Byleth's class tasked with quelling a rebellion staged by members of the Western Church who have begun rebellion against the Church of Seiros. Byleth's class faces off against one of the rebellion's leaders, lord Lonato in a misty forest. The battle ends with Lonato's death.

During the Blue Moon, defectors of the Western Church invade the Holy Mausoleum in order to steal the holy corpse of Seiros. Though the Death Knight, a mysterious yet power knight, is among their forces, he does not fight alongside them and retreats when most of them are defeated, leaving the leader to desperately open Seiros's tomb, only to find a sword inside. Byleth disarms him and claims the sword. The Sword responds to Byleth, allowing them to kill the leader. In the aftermath, Rhea is astounded that the sword has reacted to Byleth as the last person to use it was Nemesis, who held the Crest of Flames. Despite not knowing how Byleth inherited his crest, said to have been lost to history since he had no descendants, she entrusts the Sword of the Creator to Byleth as they are the only one capable of drawing out its full potential.

The Verdant Rain Moon tasks Byleth's class with recovering a Hero's Relic, a weapon said to have been forged by the Goddess herself like the Sword of the Creator. The relic was stolen from House Gautier by its former eldest son Miklan who was disowned for not having a crest. Byleth's class is able to suppress the bandits with help from Knight of Seiros member Gilbert, leaving only Miklan left. Miklan attempts to draw out the power of the Lance of Ruin, but lacking a Crest, the lance rejects him, transforming him into a Demonic Beast. It takes the entire class to take down the beast, leaving behind the lance and corpse of Miklan. The lance is safely returned to House Gautier, though Byleth and the house leader are left to ponder the true nature of the Crests and Hero's Relics.

One free day, Byleth and Sothis spend some time trying to uncover more about her origins in their Paralogue, traveling to Zanado, a place of importance to Sothis, though she does not know why. While lost in thought, they are attacked by Demonic Beasts, though they are saved by their students who had trailed them.

During the Horsebow Moon, Flayn is kidnapped, supposedly by a reaper who appears only at night. At the end of the month, Byleth discovers a hidden passage in Jeritza's room as well as a wounded and unconscious Manuela. While the house leader takes Manuela to the infirmary, the rest of the class dispatches the Death Knight's forces and is able to rescue Flayn after the mysterious Flame Emperor forces him to retreat. Byleth also discovers a Black Eagles student named Monica who had gone missing the previous year.

The Wyvern Moon gives the students a break from their monthly missions for another house mock battle competition, this time with slightly higher stakes and prizes to the winner. Despite the improvements of the others house, they are all ultimately no match for Byleth's. During the month, Jeralt takes Byleth to their mother's grave which is in the Monastery cemetery. After a heart-to-heart session, Jeralt tells Byleth to search his office for something important in the event that he dies on a mission.

Near the end of the Guardian Moon, several Academy students go missing when exploring a nearby abandoned chapel. Byleth and their class investigates the ruins only to find several students attacked by monsters. They are able to defeat the monsters, but it is revealed that the beasts were actually transformed students. Among the students rescued was Monica who thanks him. However, with his back turned, Monica takes out a dagger and plunges it into Jeralt's back. Byleth desperately uses Divine Pulse in order to prevent his death, but Thales appears in the rewound time and deflects Byleth's attempt to stop Monica. Unable to stop his assassination, Byleth holds Jeralt as he dies, crying for the first time. In the aftermath, Byleth kept grieving, until the house leader comforts them and implores them to keep moving forward as Jeralt would have wanted.

Honoring their father's late request, Byleth uncovers his diary, recounting his growing distrust in the Church and Rhea as well as Byleth's infancy. He also left behind his wife's ring, which he wanted Byleth to give to their lover when the time came for them to find their own happiness.

After learning the whereabouts of Kronya, their father's killer, Byleth confronts her in the Sealed Forest, bent on revenge, and with the assistance of the class they are instructing, they are able to corner her. However, Solon appears and sacrifices Kronya to activate a ritual, sending Byleth into a dark void. As Byleth and Sothis are left helpless, Sothis then explains that she now remembers she is the Progenitor God, and merges herself fully into Byleth, sacrificing her individuality and no longer appears before Byleth. The fusion causes a surge of power to erupt, unlocking the true power of the Sword of the Creator and granting Byleth the power to cleave a portal through the void back into the battle field. With their new found power, Solon is slain.

Upon returning to the monastery, Rhea leads Byleth to the Holy Tomb to sit on the throne to awaken their true power. Suddenly, the Holy Tomb is besieged by the Flame Emperor and some hired bandits determined to steal the Crest Stones stored there. Byleth's class is able to stop most of the bandits and recovers as many Crest Stones as they can. Left with the Flame Emperor, during a great clash, the mask of the Emperor is knocked off, revealing that Edelgard has been the Flame Emperor the entire time.

The events of the story of Three Houses differ greatly from this point. If the Blue Lions were chosen, the Azure Moon plot starts from here. If the Golden Deer were chosen, the Verdant Winds plot starts from here.

If the Black Eagles were chosen, two separate paths occur from this point. If Byleth decided to attend Edelgard's coronation as Emperor of the Adrestian Empire, they are given the option to either continue to fight for the Church of Seiros and Rhea or defect and fight for Edelgard's cause, leading to the Silver Snow or Crimson Flower chapters respectively.

Azure Moon (Blue Lions)
A month prior, the Pegasus Moon has a grand ball held for the three houses to dance with one another. That night the Blue Lions gather to reminisce their year. They soon realize that their time in the school would only last for a little while longer, they all decided that the would meet again together as a class in five years for the Millennium Festival. Dimitri, alone with Byleth, reveals that he and Edelgard are step-siblings, though they only spent a short time together. Before she left, he gifted her a dagger as a present. Nearby, he catches a glimpse of the Flame Emperor conversing with Thales. When he steps in to confront them, the two teleport away, but Dimitri discovers a dagger on the ground where the Flame Emperor was.

The revelation of the Flame Emperor's identity as Edelgard causes Dimitri to snap as his suspicions were confirmed that the two were one. Having believed to have caused the Tragedy of Duscur which resulted in the death of his father, his step-mother (Edelgard's birth mother), and countless others, Dimitri flies into a berserker's rage that not even Byleth can quell.

Her intentions revealed, Edelgard retreats and her first act as new Emperor of Adrestia is to declare war on the Church of Seiros. Byleth leads the Blue Lions as the first line of defense against the Empire, even facing off against Edelgard herself. Edelgard regrets not having Byleth on her side and the two clash, but Byleth emerges victorious. A sudden second wave of Adrestian soldiers charge the castle and its worn soldiers, forcing Rhea to unleash her true form as a dragon. Seeing her struggle against Demonic Beasts, Byleth goes against her orders and tries to help her. Thales appears on the battlefield and casts an orb of magic, causing Byleth to plummet over a cliff into the valley below the monastery. Eventually the Monastery loses the battle and the students, faculty, and knights are forced to evacuate, especially with Rhea and Byleth both going missing in the aftermath. Many would search for them, but none were able to find Byleth's body.

Byleth survived, being discovered in a river near a village where a villager informs them that five years had passed. Heading back to the Monastery, now in ruins, they find a solitary figure, a battle-worn Dimitri. The five years has changed the once chivalrous prince into a ruthless and cold warrior. Believing Byleth to be yet another specter of an important loved one he failed to protect, Dimitri heads into a local village near the monastery that had been pillaged by bandits, bent on dealing justice to them. Byleth follows him and the two fight off a horde of bandits. As the battle unfolds, Gilbert and the Blue Lion core members join the fray, fulfilling their promise to reunite. The Blue Lions are elated to have found not only Dimitri, but also Byleth who was missing for years. The sole member still missing is Dedue, who was supposedly executed after helping Dimitri escape the Kingdom after he was sentenced to death by the Kingdom's current leader, Cornelia.

With the Monastery back under their control, the use it as their base of operations as they seek assistance from the few Kingdom nobility resisting Cornelia's rule and plot to kill Edelgard to stop her conquest. Dimitri, consumed by his quest for vengeance, leads the army into aggressive battles against Imperial Forces. Their first battle is against an Imperial force tasked with scouting the Monastery after rumors of its reconstruction have begun to spread. The force's leader, Randolph is captured leading to a conversation between Dimitri and him over the sophism of their actions. While Dimitri planned on slowly torturing him, Byleth grants Randolph a mercy kill to spare him of further suffering.

Byleth follows along with Dimitri's initial goals to attack the Empire, but the prince's actions become more and more reckless. Due to both Gilbert's wisdom and Byleth's guidance, Dimitri's choices are mitigated enough that the others are not put entirely at risk. Felix's father, Rodrigue later joins, providing support to Dimitri's cause and becoming another source of guidance for him. If Dedue's paralogue has been completed, it is revealed that he is alive after rescuing Dimitri thanks to the help of the Duscur men he helped to save five years prior. With the full Blue Lions house reunited and the Great Bridge of Myrddin under their army's control, the event forces the Empire and Alliance to meet Byleth and Dimitri's army at Gronder Field in a situation that echoed the mock battle from five years prior. The clash of the three armies leads to many casualties, but the Blue Lions emerge victorious, forcing Claude to retreat and Edelgard severely wounded, but is able to escape. Dimitri vows to chase after her by himself but Byleth, Gilbert, and Rodrigue stop him from going off on his self-imposed suicide mission.

Suddenly a young girl rushes onto the battlefield and attacks Dimitri, inflicting a heavy wound. Just as she is about to deal the killing blow, Rodrigue steps in and sacrifices himself, allowing Byleth the opportunity to kill Fleche. This moment becomes a turning point for Dimitri as Rodrigue absolves Dimitri of any guilt that he may have imposed on himself by the deceased. As a heavy rain falls, Dimitri is left to wonder about his purpose. Byleth extends their hand to him, offering to continue to guide him on his path as his teacher. With the weight lifted from his shoulders, Dimitri returns to his old self and becomes more objective in his goals. He decides to first restore the rule of Kingdom back into his hands, killing Cornelia and formally claiming his birthright. Though he is nervous to greet the masses, Byleth encourages him to face them and Dimitri finds the people of Faerghus eager to see the return of the true king.

With the Kingdom back in their hands, they receive a call for help by Claude against an impending Imperial invasion of the Alliance territory. Heeding his request, Byleth and Dimitri lead the Blue Lions in quelling the invasion. Grateful for their rescue, Claude announces that the Alliance has formally disbanded with the intention of merging with Faerghus. Dimitri accepts his offer and receives Failnaught to use in his cause as Claude departs Fódlan to take care of personal business in Almyra. With even more forces at his disposal, Dimitri begins the assault on the Adrestian Empire to stop Edelgard, though this time, he is willing to parley with Edelgard. Claiming Fort Merceus by defeating the Death Knight, Dimitri dispatches a messenger to Edelgard, asking her to parley with him in person. Edelgard heeds the request and meets him and Byleth. Edelgard declares her vision for Fódlan and refuses to ally with Dimitri. Heartbroken that the two must cross blades, Dimitri returns the dagger she dropped five years earlier and the two depart ways to prepare for their final battle.

The assault on Enbarr marks the start of the final battle as the Kingdom army overwhelms the Empire's forces, including Hubert who is killed in the battle. Cornered in the castle, Edelgard unleashes her dual crests, transforming her into a Hegemon Husk, granting her incredible power. The combined forces of Byleth, Dimitri, and the Blue Lions eventually take down Edelgard, causing her transformation to dispel. Left mortally wounded, Dimitri offers her hand and another opportunity to help him build a better future for Fódlan. Edelgard instead throws the dagger at Dimitri, striking his shoulder just as he stabs her with Areadbhar, killing her. The duo depart the empire having ended Edelgard's ambitions. With the war over, Rhea, weakened by her time in imprisonment, steps down as Archbishop while Byleth assumes the title, leading the Church of Seiros. Dimitri formally becomes king of Faerghus, now comprised of the entirety of Fódlan. The former teacher and student help to lead Fódlan into a better future.

Crimson Flower (Black Eagles)
Byleth grows close to the Black Eagles house, particularly to house leader Edelgard. Should they forge a strong enough bond with her, she asks them to accompany her on a week trip to the Empire where she formally ascends the Adrestian Empire's throne as its new Emperor.

After being unmasked in the Holy Tomb, Edelgard is shocked, but elated when Byleth chooses to ally with her. Incurring Rhea's fury, they retreat to the empire.

Five years later, the teacher and student are reunited.

In the final battle, Rhea transforms into her dragon form in hopes of killing Byleth and reclaiming the Crest of Flames that they bear. A brutal battle ensues, but Byleth and Edelgard are able to kill Rhea. Suddenly, Byleth collapses and when Edelgard checks their heart, she hears no pulse. As she weeps for her teacher, the Crest of Flames dissolves from their heart and for the first time, their heart begins to beat as Sothis's power vanishes. With the Church of Seiros formally dissolved and control of Fódlan in Adrestian hands, the continent begins to see huge reforms under Edelgard's rule. Though they have lost the power of Sothis, Byleth spends the rest of their life to end Those Who Slither in the Dark and become a lifelong confidant to Edelgard.

Silver Snow (Black Eagles/Church of Seiros)
If Byleth remains true to Rhea and the Church of Seiros, they will attempt to defend Rhea during the Adrestian Empire's surprise assault on the monastery before being knocked into a ravine by a magical blast. Five years later, they lead the rebuilding of the Church Forces at Garreg Mach Monastery into a resistance army capable of standing against the Adrestian Empire and saving Rhea.

Byleth leads the resistance army to Enbarr and defeat the empire with the deaths of Hubert and Edelgard. Edelgard, in her final moments, states that for the war to end, Byleth must kill her, and Byleth personally executes her. They then learn, in a posthumous letter from Hubert, of the location where Rhea has been held in confinement for five years, as well as the existence of Those Who Slither in the Dark, who reside in Shambhala. Hubert's letter states that the land will not know peace as long as Those Who Slither remain a threat, and thus Byleth leads their army to Shambhala. Rhea, still ailing from her years of confinement, insists on seeing the enemy for herself and travels with them.

At Shambhala, Byleth defeats Thales, who in his last moments triggers a last-ditch assault of Pillars of Light. Rhea takes the form of The Immaculate One in an effort to staunch the assault and protect Byleth and the Church forces, and is gravely injured in the process. However, with the Empire and Those Who Slither in the Dark both defeated, the Church is able to begin coalescing the fragments of the former Empire, Kingdom, and Alliance into a singular nation that the Church asks Byleth to lead, as it is feared that the stresses and injuries that Rhea has endured leaves her without much time left. When Byleth has had time to ponder their decision, they approach Rhea, who asks that they first listen to what she has to say.

Rhea apologizes to Byleth personally, and explains that it was her actions that made Byleth who they are. In her desire to see her mother Sothis again, she engaged in experiments, attempting to create a vessel for the goddess. Her twelfth attempt, a failure like those before, was a young woman with the Crest Stone of the progenitor goddess planted in her heart. The woman grew up without any signs that the goddess inhabited her, and eventually fell in love with Jeralt, who by that time had Rhea's blood transfused into him. In their union, the woman grew pregnant with Byleth, but at birth, Byleth was stillborn, and their mother was on the verge of death, as well.

Byleth's mother pleaded for Rhea to save the baby, and Rhea did as she wished. She removed the Crest Stone from the woman's heart, and implanted into Byleth's still heart. Byleth was given life and a pulse, but lacked a heartbeat or the ability to express emotion. Despite this, Rhea kept her deeds a secret from Jeralt, who came to suspect her of ulterior motives and never realized that if Rhea hadn't acted, Byleth would have remained dead at birth.

As Rhea concludes her explanation and her apology, her weakened body gives out, and she is consumed by the power of The Immaculate One. Driven into a violent, uncontrolled frenzy, she becomes a threat to the whole land, and Byleth is forced to lead their forces into battle one more time to stop her. Once they defeat her, she is returned to herself, and she sees her mother in Byleth just before she passes on.

Personality
Byleth has a very subdued personality and has difficulty expressing emotion. Even as a newborn, they neither laughed nor cried. People they are especially close to, such as Jeralt, are able to tell how they are feeling despite their limited emotional visualizations. A handful of their students note that their outward expressions hardly vary. Some express surprise whenever they simply smile. According to Alois, this trait of theirs may in part come from their father, as Jeralt does not show his emotions easily either and can also be difficult to read. Due to Jeralt keeping out a lot of information about the world, they are curious about the influence of the Church of Seiros, the mystery of the Crests, and the dynamic of the three nations.

Their stoic demeanor slowly changes over the course of the Academy phase. Jeralt notices that they have become more expressive over the first few months, likely a result of the bonds they have formed with their students. Despite appearing indifferent, Byleth can be perceptive of their students and fellow faculty's problems and serve as a great source of emotional support for their issues. As the story unfolds, their emotions become more dynamic including feeling true sorrow, vengeance, and happiness.

Byleth has somewhat of a reputation from their earlier years in their father's mercenary corps for being a fearless and skilled warrior. The three house leaders of the Officer's Academy attest to their martial prowess and have deep, profound respect for their abilities and guidance in battle and in the classroom. They alongside the other students continue to refer to them as teacher or professor even after the time-skip. The three house leaders also deeply regret that Byleth had not chosen their house if they are not teaching theirs, seeing the value in their strengths.

According to Female Byleth in Heroes, she does not actually know the distinction between a friend and an ally due to their unusual childhood. Nevertheless, they are well liked by the student body, even those not in in their initial house. Their wisdom ultimately shapes the outcome of the events of Three Houses providing council and guidance to the house leader they chose to teach, helping to shape them into better warriors and leaders. Several students can develop an interest in them and eventually switch over to their house if not already in them. This results in them also joining their faction during the War, even those from enemy nations defecting to their cause, thus changing their fate. Those who do not join will often express regret facing them in battle.

Growth Rates

 * 45%
 * 45%
 * 35%
 * 45%
 * 45%
 * 45%
 * 35%
 * 30%
 * 45%
 * }

Maximum Stats

 * 88
 * 77
 * 55
 * 66
 * 66
 * 66
 * 55
 * 55
 * 99
 * }

Learnt Magic

 * D
 * Fire
 * Heal
 * D+
 * Thunder
 * Nosferatu
 * C
 * Bolganone
 * Recover
 * C+
 * B
 * B+
 * A
 * Ragnarok
 * Aura
 * A+
 * }
 * B+
 * A
 * Ragnarok
 * Aura
 * A+
 * }
 * A
 * Ragnarok
 * Aura
 * A+
 * }
 * A+
 * }
 * }
 * }

Overall
Byleth has flat stats across the board with no particularly abysmal growths save for the low 30% growth in Resistance and slightly higher 35% growths in Magic and Defense. With every other stat having a 45% growth, Byleth is a flexible unit and a potent fighter regardless of whatever class they are put in, though they have an emphasis on physical classes due to the stronger Strength growths. Their personal skill Teacher's Guidance initially gives Byleth and any adjacent ally a 20% Exp boost during combat, giving them perfect utility in strengthening their allies. After the timeskip, Byleth and their adjacent allies also gains a +2 damage boost to their attacks. Byleth's role as the main character does mean that while they are potent, they still need some level of caution used as when they fall, it instantly causes Divine Pulse to activate, thus using one of the charges.

Byleth is one of the best Battalion users as their Charm growth is the easiest to improve. By using Tea Times and choosing the correct topics, they can gain 1 Charm point at the end. Byleth also can easily make usage of Faculty Tutoring to improve specific subjects. With proper planning, this makes recruiting students from other houses much easier without having to use any of the subjects during battles.

Byleth's spell pool is fairly average with a mixture of damage from their Reason list consisting mainly of Fire based spells and a both offensive and utility Faith spells, which gives them option if using magic based classes.

Byleth's subject strengths are in Sword, Brawl, and Authority, the three of which syncs naturally with their exclusive story promotion Enlightened One. They also have a Budding Talent in Faith, granting White Magic Avoid +20 giving them extra avoid when equipped with a Faith spell. With no Subject Weakness, Byleth can apply themselves into any class possible though the Myrmidon class line is their strongest options that aligns with their affinities. Males can choose the Brawler lines as it will naturally use Brawling. With their budding talent unlocked, the Monk line is accessible. Otherwise, they can technically fit into any other class without much trouble and thus can pull skills from them as needed.

Supports
Like previous Avatars, Byleth is able to form supports with every character in game, including both Rhea and Sothis who are only able to support with them. They are also the only character in-game that is able to form an S-Support with their partner. Each gender of Byleth is able to S-Support with all characters of the opposite gender. Male Byleth can form a same-sex S-Support with Linhardt, Gilbert, and Alois. Female Byleth can do the same with Edelgard, Dorothea, Mercedes, Sothis, and Rhea.

Fire Emblem Heroes

 * -|Male=
 * Tested Professor
 * Child of the former captain of the Knights of Seiros, Jeralt. A stoic, capable professor at the Officers Academy. Appears in Fire Emblem: Three Houses.

Base Stats
Rarity: ✯✯✯✯✯

Skill Inheritance

 * -|Female=
 * Proven Professor
 * Child of the former captain of the Knights of Seiros, Jeralt. A stoic, capable professor at the Officers Academy. Appears in Fire Emblem: Three Houses.

Base Stats
Rarity: ✯✯✯✯✯

Three Houses

 * See Main Article: Byleth/Quotes.

Heroes

 * See Main Article: Byleth/Heroes Quotes.

Three Houses
Byleth - Wandering Flame
 * Byleth defeated those who slither in the dark and put down the crazed Immaculate One. In the aftermath of the loss of Fódlan's great leading figures, he/she ascended the throne as the first leader of the United Kingdom of Fódlan. In his/her heart lived the indelible hope that their efforts would one day yield an era in which the people knew true peace and the horrors of war were a hazy memory of the past.

Byleth - Guardian of Order
 * Byleth helped Dimitri to finally crush the ambitions of the Empire. After the war, Rhea stepped down from her role as archbishop, and Byleth swore to lead the Church of Seiros in her stead. He/She helped to guide the Holy Kingdom of Faerghus as it brought leadership to the newly unified Fódlan and worked tirelessly to create a peaceful world free from the shackles of oppression.

Byleth - Ruler of Dawn
 * Together, Byleth and Claude sent the Fell King, Nemesis, a foe from a bygone age, back to the flames of eternity from whence he came. Afterward, Claude left Fódlan, leaving Byleth to ascend the throne as the first leader of the United Kingdom of Fódlan. As he took his schemes and dreams and efforts to a far-off land, he hoped dearly that their joint efforts would one day allow for a world where all of humanity can co exist in peace and harmony, regardless of borders or bloodlines.

Byleth - Wings of the Hegemon
 * Byleth fought alongside Edelgard to bring an end to the tyranny of a godlike being. Though he/she was wounded in the battle and lost the power of the progenitor god, he/she remained determined to walk his/her destined path. With his/her legendary blade in hand, he/she will never stop standing against those who slither in the dark until Fódlan at last knows everlasting peace.

Male Byleth
Byleth and Edelgard
 * Byleth and Edelgard ended the tyranny of a godlike being. Byleth was wounded and lost the power of the progenitor god, but it mattered not, as he and Edelgard had each other. To ensure lasting peace, the two fought against those who slither in the dark, and to ensure a society where people can rise and fall by their own merits, they spent their lives reforming the antiquated class system. They achieved much in their time together, and it is said that they were sometimes spotted leaving the palace to privately enjoy the world they created. How they spent those precious moments, none but the two of them will ever know.

Byleth and Bernadetta (Silver Snow route)
 * After ascending the throne as the first leader of the United Kingdom of Fódlan, Byleth announced his marriage to Bernadetta. Many were concerned that the new leader of House Varley would do little more than hide, but she in fact followed the new king wherever he went and provided him with constant counsel. She never did overcome her shyness, however, and it is said that aspiring advisers who frightened her were quickly turned away. Because the ones she liked performed well in their service to the people, Bernadetta was widely believed to have a discerning eye.

Byleth and Petra
 * As Byleth set out to fight those who slither in the dark, Petra left the throne of Brigid to her family to follow him. The pair fought many hard battles together against this terrifying enemy before finally emerging victorious after the long war. Finally able to breathe easy, they took up residence in the city of Nuvelle, which lies on the western edge of Fódlan, where they enjoyed the same waters that touch her homeland of Brigid. As their love grew, so did their mastery of each other's native language.

Byleth and Mercedes (Crimson Flower)
 * Byleth and Mercedes wed in haste, that they might better focus on their battle against those who slither in the dark. The struggle was long and arduous, but their passionate love supported them through it. When at last the fight was done, they moved to a small village in the Faerghus region and started an orphanage. There they took in and raised children who had lost their families in the war, regardless of their blood or circumstances of birth. It is said that Mercedes was never happier than when she was surrounded by smiling children, free of all worry.

Byleth and Annette (Azure Moon)
 * After becoming the new archbishop of the Church of Seiros, Byleth announced his marriage to Annette. His wife actively contributed to his endeavors, and it is said her wisdom was heavily relied upon during Fódlan's restoration and development. Despite her lofty position, she was known to occasionally step in as a guest speaker at the Royal School of Sorcery, where she educated many renowned sages. Though her talents were widely respected, it is said she was a bit accident-prone. Charming tales endure of her husband saving her from countless kitchen explosions, but it is unknown whether there are fact or purely fiction.

Byleth and Lysithea (Crimson Flower)
 * Almost immediately after Byleth and Lysithea had celebrated their engagement, the struggle against those who slither in the dark began in earnest. Together they fought tirelessly to bring the war to an end so that Fódlan could have lasting peace. Afterward, they left the Imperial army for Ordelia territory, where they were officially wed. After restoring their war-torn land, the couple vanished from the public eye, along with Count Ordelia and his wife. No records remain of their lives after that, but it is rumored that they retired to a peaceful life in Derdriu, making sweets.

Byleth and Lysithea (Verdant Rain/Silver Snow)
 * Byleth announced his engagement to Lysithea shortly after becoming leader of the United Kingdom of Fódlan. Before they were officially wed, she returned home, helped her father to restore Ordelia territory, and offered the land up to be governed directly by the new kingdom. Once the affairs of House Ordelia were in order, Lysithea finally married and became queen. Even without her Crests, she proved more than capable in the role, applying her great insight and intelligence toward a better Fódlan. When the rebuilding effort was complete, the couple and their children enjoyed long and peaceful lives.

Byleth and Lysithea (Azure Moon)
 * Byleth announced his engagement to Lysithea shortly after being named archbishop of the Church of Seiros. Before they were officially wed, she returned home, helped her father to restore Ordelia territory, and offered the land up to be governed by neighboring lords. Once her parents had retired and withdrawn, Lysithea finally became the archbishop's wife. Even without her Crests, she proved more than capable of assisting him in his role, applying her great insight and intelligence toward a renewed church. When the rebuilding effort was complete, the couple and their two children enjoyed long and peaceful lives in the lively household they built together.

Byleth and Catherine (Verdant Rain/Silver Snow)
 * Byleth announced his marriage to Catherine shortly after becoming leader of the United Kingdom of Fódlan. While the king focused on the rebuilding effort, Catherine worked as his bodyguard, and when the situation called for military force, she mobilized the troops and went to battle. Under her watchful eye, Fódlan entered a new era of peace. A common saying among the people was that the king of Fódlan had two weapons: the Sword of the Creator, and his fearsome wife.

Female Byleth
Byleth - Ruler of Dawn / Wandering Flame and Seteth - Heir of Purpose (Verdant Wind/Silver Snow routes)
 * After ascending the throne as the first queen of the United Kingdom of Fódlan, Byleth appointed Seteth as her prime minister. As they set about the grand task of restoring Fódlan, the prime minister’s strictness combined with the queen’s magnanimity won the people over easily. Their personalities complemented one another perfectly in dealings with obstinate lords. When their long work was done, they finally announced their marriage, to the shock and delight of their subjects. The people considered themselves truly blessed to be governed by such a union.

Byleth - Ruler of Dawn / Wandering Flame and Alois - Sun of the Knights (Verdant Wind/Silver Snow route)
 * After the war, Byleth ascended the throne of the United Kingdom of Fódlan, and Alois retired from the Knights of Seiros to serve the former professor. Alois became the new leader's right hand, and his duties in that respect kept him busily engaged all over Fódlan, giving all he had to support her reign. Alois's cheerful character was beloved by his subordinates, who rallied behind him to create the most numerous order of knights in all Fódlan. It is said that Byleth relied on Alois as though he were her own father.

Byleth - Ruler of Dawn and Cyril - Limitless Potential (Verdant Wind route)
 * Byleth declared the founding of the United Kingdom of Fódlan at Garreg Mach and ascended the throne as its first leader. Cyril served as a chamberlain, supervising all general affairs. With the expansion of the kingdom, it was eventually decided that the queen would move to a new royal capital. Cyril wished to accompany her, but was ordered to enroll in the newly reopened Officers Academy. Though reluctant, he complied. A year later, after consistently demonstrating great wisdom and maturity, he won the queen's heart, and they announced their abrupt marriage. The move surprised many, but no one was as shocked as Cyril himself was pleased.

Byleth - Guardian of Order and Dimitri - Savior King
 * Paired with the end of the war, the joyous marriage of Byleth, the newly-appointed archbishop, and Dimitri, the newly-crowned king of Faerghus, gave the people of Fódlan much to celebrate. The two were devoted to improving life for the people and to seeking greater wisdom in order to reform the government and the church from the inside out. As leaders of church and state respectively, at times they engaged in heated debate. Even still, when enjoying a long horse ride or a quiet evening, they were not as the world saw them, but rather two adoring spouses, desperately in love. They remained as such for the rest of their days.

Byleth - Guardian of Order and Dedue - Taciturn Devotee (Azure Moon route)
 * A year after Byleth was appointed to succeed Rhea as the new archbishop, she announced her marriage to Dedue, who had resigned his position as the king's vassal. Their wedding ceremony, brightly colored with all of the most beautiful flowers from Duscur, set the tone for their happy life together. Dedue served as an intermediary between Faerghus and the church and -- alongside the archbishop -- committed to improve relations with foreign nations as part of the rebuilding effort. In their later years, they retired to the Duscur Peninsula where they spent the remainder of their lives gardening in peace and quiet.

Byleth - Guardian of Order and Felix - The Shield's Successor (Azure Moon route)
 * Byleth married Felix, who had become Duke Fraldarius, shortly after she was named to succeed Rhea as archbishop. Felix focused his efforts on restoring his territory and the Kingdom and became the archbishop's closest confidant, both privately and officially. They often spent a lot of time apart, but whenever they reunited, they had a tradition of crossing blades before crossing words. Attendants remarked that the smiles they wore on their faces during these bouts were never seen elsewhere.

Byleth - Ruler of Dawn and Felix - Meandering Sword (Verdant Wind route)
 * Byleth married Felix almost immediately after ascending the throne of the United Kingdom of Fódlan. When it came to matters of governance, Felix often took on duties that would have required his wife to dirty her hands and thus came to be called The Royal Sword. After they accomplished all they had set out to do, the couple left the rule of Fódlan to the next generation, disappearing into obscurity with blades in hand. Thereafter, history only provides unconfirmed reports of a pair of traveling mercenaries who possessed unmatched strength and skill.

Byleth - Guardian of Order and Ashe - Arrow of Justice (Azure Moon route)
 * When Byleth became the new archbishop of the Church of Seiros, Ashe served her faithfully-first as a knight and aide, and later as a husband. With help from Faerghus, the archbishop put much toward the rebuilding effort with particular attention paid to relief for orphans in the form of food, beds, and even schooling. It is said that these compassionate deeds were all Ashe's suggestions, but the modest knight always gave the credit to his beloved wife.

Byleth - Ruler of Dawn and Ashe - Arrow of Justice (Verdant Wind route)
 * When Byleth ascended the throne of the United Kingfom of Fódlan, Ashe served the new leader faithfully - first as a knight aide, and later as a husband. The queen, with help from the Church of Seiros, put much toward the rebuilding effort with particular attention paid to relief for orphans in the form of food, beds, and even schooling. It is said that these compassionate deeds were all Ashe's suggestions, but the modest knight always gave the credit to his beloved wife.

Byleth - Guardian of Order and Sylvain - Sincerest of Knights (Azure Moon route)
 * After becoming the new archbishop of the Church of Seiros, Byleth announced her marriage to Sylvain, heir to House Gautier. Sylvain was a valued ally who assisted his wife in her new role, both publicly and privately. He achieved a great deal, including fostering relations with Faerghus and helping to institute sweeping organizational changes within the church. Though known as a philanderer in youth, Sylvain happily settled down after marriage. By the time he inherited the title of Margrave Gautier, he was a gentle and devoted husband. It is said that those who knew him in his youth wondered what sort of spell the archbishop had cast on him.

Byleth - Ruler of Dawn and Sylvain - Sincerest of Knights (Verdant Wind route)
 * After ascending the throne as the first leader of the United Kingdom of Fódlan, Byleth announced her marriage to Sylvain, who had become the new Margrave Gautier. Sylvain was a valued ally who assisted his wife in her new role, both publicly and privately. Most of all, it is said that his cunning manner of speech was a great asset for fostering relations between the Church of Seiros, Fódlan, and surrounding regions. Though known as a philanderer in youth, Sylvain happily settled down after marriage and became a gentle and devoted husband and father. The two had many children whom they doted on equally, regardless of whether or not they bore a Crest.

Byleth - Ruler of Dawn and Ignatz - Worldly Artist
 * Byleth announced her marriage to Ignatz shorty after becoming the leader of the United Kingdom of Fódlan. Ignatz supported the restoration of Fódlan as Queen's spouse, but became better known for his skill with a paintbrush. He donated beautiful portraits and landscapes to churches all over the kingdom, and it is said that his works provided great comfort to those touched by the war. His most famous price, entitled Descent of the Goddess, depicted the eponymous deity descending form the heavens to lead the people. Those who knew the queen often remarked that her face must have been used as a reference.

Byleth - Ruler of Dawn and Claude - King of Unification
 * After ascending the throne as the first leader of the United Kingdom of Fódlan, Byleth sought to rebuild the war-torn towns and villages and to help guide the reformation of the Church of Seiros. After a few months of peace, remnants of the Imperial Army joined with those who slither in the dark and marched upon the capital city of Derdriu. The new kingdom lacked the power to repel the invaders, but when defeat seemed imminent, a battle cry rang out from the east. Claude, the newly-crowned King of Almyra, led a mighty army that broke through the rebel forces with ease. This show of solidarity forever altered the course of history, heralding a new age of unity.

Byleth - Ruler of Dawn and Lorenz - Noble of the Red Rose (Verdant Wind route)
 * Byleth announced her marriage to Lorenz shortly after becoming leader of the United Kingdom of Fódlan. Lorenz took equally well to his dual roles as the queen's husband and the leader of House Gloucester, working simultaneously to restore his own territory and to advance the development of Fódlan at large. Because his policies were of particular benefit to the commonfolk, he was well loved, and came to be called the Lord of Roses. After many years of peace, Lorenz grew ill and withdrew from the public eye. The queen followed, entrusting the throne to the prince. It is said that he was the spitting image of his father.

Byleth- Wings of the Hegemon and Raphael - Beast of Leicester (Crimson Flower Route)
 * Byleth and Raphael celebrated their marriage with a small but lively wedding. Almost Immediately afterward, the battle with those who slither in the dark began in earnest, and Raphael devoted himself wholly to his wife's protection until the chaos of war was finally quelled. It is said the great affection between the two was viewed by many as a symbol of the new era of peace that followed. They were long remembered, even after they stepped back from the public eye, thanks to portraits painted by Raphael's sister, Maya.

Byleth - Wings of the Hegemon and Hubert - Emperor's Confidant
 * After a fierce battle, Byleth and Edelgard finally brought the tyranny of a godlike being to an end. Though wounded in conflict and stripped of divine power, Byleth continued to fight alongside the emperor to bring true peace. Hubert joined them in this fight, fulfilling his promise to confront those who slither in the dark head-on. In that darkness, Byleth and Hubert formed an unbreakable bond. It is said that, as a married couple, they were totally inseparable.

Byleth - Wings of the Hegemon and Linhardt - Ragamuffin Sage (Crimson Flower route)
 * Though grateful for the end of the war, Byleth and Linhardt were disappointed to see that there was no time to relax. The fight against those who slither in the dark began immediately, and Linhardt abandoned his territory to help fight for a world of peace and quiet. Though the struggle was bitter, he took heard in the knowledge that once it was over, he and Byleth could spend the rest of their days in leisure, chasing idle pursuits far away from the stage of battle.

Byleth - Wings of the Hegemon and Ferdinand - Noblest of Nobles (Crimson Flower route)
 * Byleth and Ferdinand celebrated their marriage with a lavish wedding, but almost immediately afterward, the battle with those who slither in the dark began in earnest. After being named Duke Aegir, Ferdinand overcame a slew of obstacles to help House Hrym and his family's territory recover. At the same time, he fought alongside his spouse for a true, lasting peace in Fódlan. History books extol Ferdinand's success as a lord of his territories, but they do not make mention of the hard-fought battles he endured alongside his wife. Thus, half of his life's work is lost to time.

Fire Emblem 0 (Cipher)
Byleth is illustrated in the trading card game Fire Emblem Cipher with the following cards:

Etymology
Byleth is a variation of Beleth, a king of Hell. According to Pseudomonarchia Daemonum, Ham, Noah's son, was the first in invoking him after the flood, and wrote a book on mathematics with his help.

Eisner, Byleth's surname, is a German name related to various iron-working occupations such as smithing.

Trivia

 * Byleth's default name in Japanese differs slightly between genders, as a male Byleth is spelled "ベレト" (Bereto), while the female is "ベレス" (Beresu).
 * Byleth's male voice actor, Chris Niosi, was replaced with Zach Aguilar in an update released for Three Houses on September 10, 2019. Aguilar had previously replaced Niosi's role as Byleth in Fire Emblem Heroes, though Aguilar's lines were swapped in via an update before the character Byleth: Tested Professor became properly available to players.
 * Byleth's artwork shows them wielding the Sword of the Creator.
 * Byleth is the first Avatar character since Mark to not feature a customizable appearance. Their male and female designs are fixed and cannot be edited by the player.
 * Byleth is the first character in Fire Emblem Heroes to be made available either through regular summoning, or via recognition of another game's data. At the launch of Three Houses, Heroes players that play both games on the same Nintendo Account will receive a free Byleth unit.
 * Byleth is the first avatar to fully appear in animated cutscenes without being obscured in some manner from a third person view or watching scenes unfold from a first person perspective. This is due to Byleth's lack of customizable physical features.
 * Byleth is the first and only Avatar character to be referred with neutral pronouns in the game. Because the game is fully voiced, characters use different monikers and titles to refer to Byleth (hence avoiding having to voice the name the player chose), and the use of titles and neutral pronouns allows the same dialogue to be used for both genders of Byleth without the need to record separate lines. Gendered pronouns are used in the game's epilogue and some tutorial text, which are not voiced.
 * While the player chooses Byleth's birthday, the default birthdate is 20th of the Horsebow Moon (September 20th) 1159, a significant date in the story and reinforced by information from Jeralt's journal.
 * If, during a New Game+, the Holy Tomb is visited via the amiibo Gazebo at any point after Chapter 10, the opposite gender version of Byleth will be found there. Byleth can be talked to, but they only speak in ellipses.
 * Male Byleth stands at 175cm (or about 5’9”), while female Byleth stands at 164cm (or about 5’5”).
 * Byleth is the first Avatar character to have a defined difference in height between genders.
 * In a survey conducted by Nintendo DREAM Magazine, female Byleth placed 3rd with 17.7% of the vote overall and ranked 4th with 16.6% among those who completed the game in the character popularity poll for Fire Emblem: Three Houses. The male-female vote ratio was 1:2.
 * In the same poll, Male Byleth placed 6th with 14.3% of the vote overall and ranked 8th with 13.0% among those who completed the game.
 * Female Byleth is the only Byleth capable of S-Supporting all three Lord characters and has 23 S-Supports compared to Male Byleth's 20.