Amon

Demon Lord of War, Amon is one of the most imensly powerful demons in all of Hell. His destruction on Earth and his affair with Sirene were known throughout Demon Realm. It was when he attempted to posses Akira when he lost control giving birth to DEVILMAN. However, during Miki's murder he is able to gain back control and goes on a killing spree. Eventually killing humans, demons and attacking Satan. He is then challenged by Akira for possession of his body. Amon had the upper-hand but eventually was defeated by Devilman.