Well, something like this happens ig. Collector goes through a supernova phase it between (where his physical form burst like, yknow a supernova) this is how it went

Anatomy, ok I think I've proved my point enough

Well,, yes (His cosmetics? )

Ok this is a funny one (bc I was being delusional after wad but, meh) I think this comic explains it in short, collector ended up staying in the isles, fixing up their mess, learning about the isles and the people etc till they decided to leave after the kingceañera-

IN THE MAKING