Disclaimer: I don't own Kingdom Hearts
Axel comes back as a disembodied voice in someone's head. This wasn't what he had been thinking of when he said "next life" but it's fitting really. He was nothing in that world and he is nothing in this, just a shadow of someone's mind.
Or maybe he'd just been listening to Xenmas too much back then. That was more than enough to make him starting thinking rubbish like that.
The view from someone else's body is not too great; his vision flickers like the broken down box with the pictures his person spends too much time watching. His occupant is overweight too, and Axel hates that. He never honestly believed he could ever long for his lanky, tall body. It was empty true, it had been a shell but it had been his. Everything is out of control now, even worse than before.
Axel spends too much time thinking, but what else can you do? He's afraid of ever trying to look down, of what he might see (of what he might not see) so he floats and he thinks. Did the others come back or did they find Kingdom Hearts. Did they…
The thought of that what was left of the Organization had found their hearts that they could die, could die for good was horrifying. So he focused on the ones he knew must have shared his fate. Was Larxene the doped up teenager he passed to buy food, Marluxia the oddly colored red dog who lived next door?
He tries his best not to think of Roxas, best friend in my sick fucked up, not caring way, Roxas. Axel knows Roxas is not anywhere here, that he could search the world and not find Roxas, because Roxas has gone on. He found his Other and whenever Sora died, whether at the hands of Xenmas or of old age, Roxas went with him.
Axel feels the water running over the man's hands (distant and smooth, like someone numbed his fingers and dipped them in a river) and knows he'll be going to sleep soon. Axel will go with him, more out of boredom than actual necessity.
And then, far too soon, tomorrow will come.