I want Isla to be completely gone. Otherwise, everything the show built up to becomes pointless. It would be even better if the new Giftia that looks like Isla shows utter disregard of the dude, but he doesn't care either because he knows she's not the same person. He shouldn't shy away from making new bonds and keep being the nice guy that he is. That shows his growth as a person and as a spotter, giving meaning to Isla's life outside of just memories.

He can get together with tsundere girl after grieving for a while. She wants him, and he doesn't seem to hate her. It just so happened he was already in love with Isla from the very beginning and never gave her a chance.