Fomortiis is a giant horned demon known as the Demon King and is the true main antagonist, as well as the final boss of Fire Emblem: The Sacred Stones.
In the year 3, the Five Heroes trapped the Demon King's soul using the Sacred Stones. The stone of Grado (also known as the Fire Emblem) holds the soul of Fomortiis. Eight-hundred years later in year 803, Vigarde, the Emperor of Grado, dies and his son Lyon then tries to bring him back to life using the power of the Sacred Stones. Lyon succeeds, but in the process gets possessed by Fomortiis (Eirika's route) or has his darkest emotions and thoughts strengthened by the Demon King (Ephraim's route).
Regardless of the route the player picks, after Lyon's death, Formortiis manages to resurrect himself. He fights Ephraim, Eirika and their allies, but is unable to withstand their assault. Defeated, the two seal his soul in Sacred Stone of Rausten before they destroy his body, to ensure that he will never be resurrected again.
Fomortiis doesn't take possession of Lyon's body, instead merely manipulating his darkest thoughts and emotions in order to make the prince himself work for his benefit. While Lyon acts on his own free will, he is unwittingly full of the emotions and fears chosen by Fomortiis to take over his mind.
Upon Lyon's death, Fomortiis decides to take a different approach, attacking his enemies directly.
Free of his prison, Fomortiis begins his reign of terror once more and invades Renais seeking to destroy its Sacred Stone using Vigarde and Lyon as his puppets. When he fails to locate the stone and the means to destroy it, he moves on to Frelia, where his generals Selena and Caellach easily overpower the Frelians and destroy their Sacred Stone.
Fomortiis then sends Caellach to Jehanna, where he kills Queen Ismaire and destroys the stone. Afterwards, both generals Caellach and Valter are slain by twins Eirika and Ephraim in Jehanna's desert. Angered, Fomortiis (still possessing Lyon) goes to stop the twins himself and destroy the stone they possess; he fails and retreats.
Fomortiis then tricks Eirika into handing him over the stone of Renais by posing as Lyon and the stone is destroyed. The twins venture to Rausten while Fomortiis travels to his temple in Darkling Woods to revive his body. Fomortiis then sends his last remaining general, Riev, to destroy the stone of Rausten and kill the Divine Emperor Mansel. Riev fails and retreats into Darkling Woods, where he is eventually slain and the twins gain entrance into the Black Temple of the Demon King.
Help Description: The Demon King, lord of darkness. His sole desire is to remake the world.
Subjective: The following part of this article is subjective to the editor's writing. Therefore, it may not work for everyone.
Fomortiis will be a doubtlessly difficult enemy, even if you trained all your units constantly with monster encounters. His Demon Light is extremely powerful and possess the range up to a Longbow. He also uses Ravager, which is a uppercut jab which can deal very high damage and can kill weakened targets. Both Demon Light and Ravager also provide Formortiis with stat boosts which make it even harder to get high damage through.
Formortiis also has access to Nightmare, which, despite having a hit chance of 70, will send every player unit in its range to Sleep for five turns without fail. Restore can work but considering that it hits multiple units if they are within range, Latona is the only way to counter it. In addition, Formortiis can occasionally summon 8 monsters (Wights, Entombeds, Deathgoyles, Arch Mogalls, Gorgons, Elder Baels, Maelduins, Cyclops, Gwyllgis and Draco Zombies) to assist him in battle.
Unlike most other endgame bosses which are incapable of moving, Fomortiis can and will move to attack targets in his range. Players should be careful not to get a weak unit nearby or he will kill them quickly.
- Fomortiis has a very unique death animation. Instead of vanishing (as when you kill a unit), his body slowly disappears, starting with his arms and what should be his legs to his face.
- Fomortiis is one of the several final bosses in the series to move. The others are Idunn, Duma, Ashnard, and Garon.
- Fomortiis is one of only two in The Sacred Stones who does not have a battle quote nor death quote, the other being Morva.
- Fomortiis is never referenced by name in dialogue, only being referenced as Demon King. His name is only used for his in game unit name.
- In Rogues and Redeemers 2, Lyon attempts to coerce Priam with promises of limitless power. He explains that he only needs Priam to meet a "friend of his", referring to Fomortiis, before Priam turns him down, sensing that something about Lyon's offer was amiss.