I'm Tired of Being the Demon King So Let's be The Hero

As war rages, a single man sits upon a throne, his eyes fierce and his magic heavy as a legion of undead bow before him. He is Carnage, the Demon King who has after hundreds of years of bloodshed, finally achieved his most valuable quest. Revenge, revenge on those who seven hundred years ago let his orphanage burn to the ground. A kingdom stricken with strife and poverty finally meeting its end. But what now? Having almost completely wiped out humanity on Iris, and clearly being the most powerful being to ever walk the land. What was his next quest for greatness? Or maybe something even simpler, to see what was on the other path he could have taken. One of justice, faith, heroism, and pride. So with his power, he creates a new world similar to the one he had lived in all those years ago. Will it be simple for someone who was once the Demon King to walk the path of a hero, or will his patience run out before he can even start.