Guessing Robin is likely Wish Robin, as we could see what he and Split Evil Queen are up to. Cruella could either be in a flashback or we see her in the Underworld. Pan, on the other hand, has to be a flashback or something else (Like a Wish version of Pan?), because his soul was sent to the River of Lost Souls.
If Malcolm and Cruella do return from the dead, I can see Faciliar have something to do with it. After all, he has “Friends on the Other Side” as he always says.