Rudolf

"Alm... You've become a splendid young man... Was it no mistake to have entrusted you with Sir Maisen after all...? You should have realized it by now, haven't you? Your real name is Alphine Alm Rudolf. My... one and only... son... Guh... I cannot speak for much longer... However, Alm. I have just one last request. Using "Falchion", that holy sword that sealed Mila... Defeat... the evil god... Doma..."

- Upon Rudolf's defeat in Chapter 4

Rudolf is the king of Rigel and one of the main antagonists of Fire Emblem Gaiden. About 16 years before the start of Gaiden, Rudolf took his newborn son Alpine to the Sofian general Maisen and left him in the knight's care, explaining that he planned to one day erupt Barensia in war in order to provoke the true heroes into rising up and stoping him and creating a new era in which the people were free from the gods, whose overinvolvement was leading mankind to ruin. Several years later, Rudolf befriends a man with amnesia who was found by Teeta, a Rigelian saint, and names the man Zeke. Rudolf became like a father to Zeke and promoted him to a high rank within the army of Rigel. One day Rudolf tells him that if he should find someone with a cross-shaped birth mark on their right arm, then he should dedicate everything to this person, as this person would be the savior of all Barensia.

Rudolf then begins his plan, requesting the Falchion from Doma in order to seal Mila, and aiding Dozah in his rebellion in order to provoke the true heroes to come out and stop him. Before his army's final battle, Rudolf praises his soliders for how admirably they had fought for him to this point and commands them to lay down their weapons and surrender if he is killed. The Rigelian army then does battle with the army of Alm, although Rudolf refuses to attack Alm. As he is dying he reveals that he is Alm's father and shows pride in the man he has become before requesting that Alm claims the Falchion and defeats Doma.

In Game
As previously stated, if Alm attacks Rudolf or if Rudolf attacks Alm, then Rudolf will not attack/attack back. This is the only real method that the player can use to beat him (unless they level grind for a very extensive amount of time), as in addition to being equipped with an Angel Ring (which essentially boosts his critical rate by 20%), he has very high HP (52, the max HP of the game for all units except the final boss), attack, defense, and speed. Assuming the player has refrained from serious level grinding, he will generally be able to double any unit that attacks him, and given that the highest amount of defense your units will generally is 20 at best (and this would only include your Baron's), he will do an average of 14 or more damage given the fact that he has a high critical rate. If not for the fact that Rudolf will not attack Alm in battle, Rudolf would likely be the most difficult boss out of all the Fire Emblem games given his high stats and abilities, along with the fact that he moves.

Boss Stats
|Gold Knight |20 |52 |27 |16 |21 |40* |22 |6 |9 | - |Lance Angel Ring

* Due to equipped Angel Ring

Trivia

 * Rudolf's first name is unknown, as his son Alm's full name, Alpine Alm Rudolf, clarifies that Rudolf is the family name. This makes him one of the only Fire Emblem characters to be referred to only by his last name.
 * Rudolf doesn't have facial hair in the Manga adaption, but he has facial hair in the Game.
 * He also wields an axe when only Thieves can use axes in Gaiden. Gold Knights would be able to use axes in later games, however.