Lazy_writer
More important than deciding the worlds you should think about the enemy. If he just went to those worlds to just do the original MC's work it would be boring in the long run. In my opinion you should create some kind of extra dimensional enemies, race, world eaters, evil gods, maybe some kind of nightmare that feeds on fantasy worlds or something like that, although you can also create multiple different final enemies and the MC would have to eliminate his agents and the damage they cause to the world. My decision has already been made. The King's judgment is absolute.