Not all anime Demon Kings are inherently evil, but all of them are most certainly overpowered MCs and are not to be trifled with.

Diablo, a Primordial demon, defies norms by working tirelessly ... That Time I Got Reincarnated as a Slime is an isekai anime ...

Demon Slayer didn’t just raise the bar for anime fights scenes; it picked it up and launched it into the stratosphere with breathtaking choreography!

Isekai anime often ... to undo the act. Diablo must set out into this new world with his companions to find a solution and learn to handle the position of the newly summoned demon lord.