OKay.
Axel spoke of another life and it got me thinking maybe Axel would stay a nobody. Yes I know he didn't have a heart and probably didn't know where his heartless was, but I think that he cared some much about Roxas that his heart might have returned to him after he disappeared. Nobody aren't supposed to have feelings for anyone while Axel was best friends with him and also said "I would miss you." He also tried to save Sora. Maybe his heart was resonating with his Nobody and he had his heart returned to him after defeating himself.
Anyway this was just me thinking. There are possibly some flaws in my theory, but I happen to think he might return in another future game.
Axel spoke of another life and it got me thinking maybe Axel would stay a nobody. Yes I know he didn't have a heart and probably didn't know where his heartless was, but I think that he cared some much about Roxas that his heart might have returned to him after he disappeared. Nobody aren't supposed to have feelings for anyone while Axel was best friends with him and also said "I would miss you." He also tried to save Sora. Maybe his heart was resonating with his Nobody and he had his heart returned to him after defeating himself.
Anyway this was just me thinking. There are possibly some flaws in my theory, but I happen to think he might return in another future game.