Yami no Ou, known in Japanese as 闇の王, is a major antagonistic figure in Final Fantasy XI. He is the dark ruler tied to the Shadow Lord and the ancient conflicts that shaped Vana'diel's history. As a central force of darkness, he represents destruction, corruption, and the lingering threat of the past. The character serves as a key boss and story element, driving much of the game's early epic narrative and the struggle between light and darkness.