A new quiet life

It is over. He finished his not-so-eternal battle. He RIPPED and TEARED. Each and every demon. His fight is over. But now what? He isn't just going to stay in the Fortress of Doom for thousands of years, that's boring. But one day, an idea struck him. Instead just staying in the Fortress of Doom, why doesn't he go into a vacation? Somewhere, in another world. But what world?