Reincarnated as Vegito... in the wrong world?

This... is not a story I expected myself to be making, but all in all I guess it goes like this...

This story is about a man in Japan no older than 23, named Kato Nakamura, who in his sleep finds himself in a new world he vaguely recognizes in a body that isn't his normal one. Join our protagonist as he explores a very heavily dense world of heroes in the body of history's most powerful saiyan fusion.