I think the guy who said that is a monester being that snatched the original body owner's brain. And he might be the one who visited the lady after monster hikari left
Since Hikaru ain't the great brain snatcher, it just mean he's some other whole being. But it's also a being that can grants wishes, since he grants real Hikaru wishes. (Plus he has memory of granting wishes). We still don't know all of it, but maybe the gojo guy will explain it in the next chapter.
well, he could be what the real hikaru wished for
What does he mean Hikaru is not the great brainsnatcher what is he then??? By now somebody pls explain the whole story cause wtf