Replacement.

[legoboss_n]

The previous Mello is gone, but another Mello has come to take his place. That's how this prison works: everyone is a replacement of others who are no longer here.

I have observed that the people I've meet from other universes didn't even come from the same one. It makes me wonder how many alternate universes there are supposed to be, and which one of them should be the original, if any.