Van Hohenheim, known as Otou-sama in 'Hagane no Renkinjutsushi' (Fullmetal Alchemist), is the enigmatic and distant father of Edward and Alphonse Elric. A powerful and immortal alchemist, Hohenheim possesses vast knowledge of alchemy and a mysterious past tied closely to the origins of the Philosopher's Stone and the Homunculi. His actions and revelations play a crucial role in the series, ultimately shaping the Elric brothers' quest and the fate of their world.