There's this one story I found pretty fun; it starts like the MC is isekaied as the "first cannonfodder villain", you know, like Mizuki in Naruto or Kuro in One Piece or Riser Phenex in DXD, anyway, and he's like, oh, I'm gonna die, but then he realizes "he" has isekaied as like three of them, and each version of the MC has all of their powers, and they got this "connected space" where they can store/share memories