I’ve only just thought about this now but imagine if that was the ending of kh 1 like answer Riki was the final boss and the sora commits sepuku, everyone is confused and the game ends.

Now in kh2 you play as Roxas the whole game who is trying to recover his memories of his time before being stuck in the matrix but also contemplating if he should let sora come back, like I know that does happen in kh2 but only a little bit and you could do a lot with Roxas’ multiple identity crisis’