NoNameDeity
Dude since it's a multiverse fanfic you should make him go in Tower Of God he can earn lots of stuff there like S class weapons or even crafts from the workshop he might find a way to have a generator shinsu but in real life he might be trying to get the power to become an "Axis user" that would allow him to control reality for example in the tower of god Phantaminum uses him to be the author of the history