This tag is only used if the main protagonist was transported into another world with the existing body & soul, part of a soul that reincarnated or just the part of a soul that inhabits someone's body to another world and came back from the place where the existing body & soul or part of a soul originally came from. The part of a soul that returned from another world may be reincarnated, inhabits an existing body, or came back from the original body of the main protagonist. There are no restriction for the place or world where they originally came from.