The Fallen God was once a god. However, he had always planned to take over. He simply waited for his power to grow, and corrupted several angels, turning them into demons. He and his brother, Galamoth, lead the attack against heaven, Galamoth with the Crimson Stone and the Fallen God with his winged cross necklace. The Fallen God was killed, but Galamoth escaped, and took the title of Dark Lord. The Fallen soon resurrected himself, but was much smaller and weakened. He attempted to destroy the world, and almost did so, but for once, the forces of good and evil joined to defeat him. His right arm and legs were severed, and Walter captured him, imprisoning him in the Castle basement. He was eventually forgotten, giving him his other title, "The Forgotten One", and began to slumber. Very rarely, heroes ventured into his lair, and were killed quickly. However, one day, Leon stumbled into the chamber, and awakened the Fallen God. The Fallen broke out of his restrainers to kill Leon, but was killed, and Leon absorbed his power source, the Black Orb. The Fallen God returned to the Underworld, and began to slumber once more. A thousand years later, he was encountered by an ancestor of the Belmonts, and now at full power, attempted to kill him. He failed, and was killed again.
The Fallen God's first form is a human-sized one-eyed demon. He will jump around the battlefield, casting fire rain. When he is far away, he will dash towards the player and rapidly punch them, paralyzing them as well. When close, he may hold his fist out, causing flames to explode forward. He has 2000 HP in this form.
The God's second form is now a purple and silver winged demon. He will fly around the room, occasionally diving to attempt to kill the player. He can also summon lightning spheres. Later, he can shoot black thunder spheres and shoot out streams of lightning that also drain MP. He has 2000 HP again.
The third form once more has wings. He has his previous attacks, can use a giant demon arm in an attempt to grab the player, and he can summon shadow tentacles. He has 2000 HP. The theme for the first three forms is You Goddamned Bathead.