It is unknown what occupation Akuma had before his Umbral Transformation, nor why he tried to control the powers of Darkness, but it is thought that he was a criminal, attempting to go on an unstoppable crime spree. It is also known that he had long, blonde hair, due to it still being visible in his monstrous state. Like all Umbrals, he made a mistake in his Manipulation training and the darkness he was controlling turned on, and consumed him. However hiding within those shadows was one of the only Diavolos that escaped extinction by stepping through an inter-dimensional rift. This caused the Human and the Diavolo to merge into one being. After going on a destructive rampage, tearing apart an entire city and killing thousands in his wake, he was found and "tamed" by another Umbral named Kagai and was enlisted into the folds of an Ancient Brotherhood, known as The Children of Darkness. He was given the name Akuma by Kagai himself, and the name truly fits along with the Umbral's nature.
After the Makata Invaded, Some members of The Children of Darkness began to go into hiding. But Akuma stayed with his master, Kagai, and those who pledged complete loyalty towards him. He seems to enjoy attacking Mutant Alliance Forces, as they pose more of a challenge to him then the Aliens, but sometimes he attacks Human survivors, and Resistance forces just for the fun of it. He has become the stuff of nightmares in the Post Apocalyptic World, and for good reasons too.
Akuma's transformation took away most of his ability of sentient thought, but he was still able to understand Kagai's proposition, and though he was unable to voice his opinion, Akuma followed him back to the Brotherhood's lair, and became one of them. So Akuma does have some sentience left, however, he fights as a berserker and uses large amounts of his power to destroy even the weakest of opponents, which the other Brotherhood members deem as overkill.
It seams he has something against Sergeant Rogue, as he has engaged him in combat on multiple occasions. Rogue's ability to turn intangible has saved his life each time. It is assumed that Akuma knew Rogue before his transformation, and had some kind of rivalry with him. But it could also be that Akuma seeks out the strongest fighters on the battlefield, and since Rogue is one of Amalgam's force commanders this could explain why he's confronted him so many times.
Like many Umrbals, Akuma didn't gain the ability of Darkness-Manipulation like he wanted. Instead he got:
- Monstrous Appearance: Akuma's body changed drastically during his transformation, giving him pure white skin with red, tattoo-like, markings along his arms, legs, tail, and face, and a black spot in the center of his chest. He grew sharp claws, a huge jaw filled with razor-like teeth, and a long tail which is the same length as his body.
- Immense Strength: Akuma can knock over an entire building in a single blow.
- Extreme Durability: Akuma's body went through many changes during his transformation, giving him diamond-hard skin and bones that can only be peirced by high calibur rounds and large explosions.
- Advanced Speed: Though not as fast as some Level 5 Speed-Mutants, Akuma can easily run as fast as a bullet train. Using this speed, he can run up the side of buildings, and combine it with his strength to jump long distances.
- Near Instantaneous Regeneration: If Amkuma somehow gets injured, despite his extremely dense body, his wounds regenerate almost instantly.
- Energy Manipulation: Akuma can fire intense waves of energy from his hands and mouth, usually having enough power to wipe an entire city block from existence. The energy is usually a dark, blood red color.
- The word Akuma means devil, demon, fiend, Satan, or evil spirit in Japanese.
- The images are that of Full-Hollow Ichigo from the anime Bleach