The Cube War

He transmigrates straight into the body of the strongest devil, but he's still a complete dumbass! In this harsh world, where dumbasses struggle to survive, he uses his overwhelming strength to do whatever he wants and commits every foolish act imaginable. He gathers a bunch of devilish problem children, and together they support one another, become the saviors of evil, use evil to punish good, and eventually slay gods and demons and unify the Six Paths!