The Demon King (悪魔王 Amaō) is an enemy-only Monster class that is exclusive to Fire Emblem: The Sacred Stones. The personal class of Fomortiis, overlord of the demons plaguing the continent of Magvel, the Demon King class employs an arsenal of monster weapons to damage its foes, including Demon Light, Nightmare and Ravager. Unlike the majority of final boss classes, the Demon King class is capable of moving. The class also possesses the Summon skill, one that it liberally exploits to summon second-tier Monsters such as Draco Zombies instead of Phantoms into battle.
Curiously, the Demon King class has the highest maximum stats for a unit in any game to appear on the Game Boy Advance. These high caps are not reached on any difficulty, making the further increase in the localization even more curious.
If these caps are reached, then the Demon King is nigh impossible to defeat, even with type effectiveness.