Ok, forgive me here, 'cause this has probably been stated before, but I'm new to the board, so here we go:
Here's what we know about losing your heart and recompletion:
1. Person loses heart to darkness. Heart becomes/is trapped in a Heartless.
2. Empty shell is left behind with no heart- a Nobody.
3. Eventually, all Nobodies will grow new hearts.
4. When a Heartless and corresponding Nobody are destroyed, they recombine into their original form.
Now, correct me if I'm just missing something, but what happens to the EXTRA heart (form step 3) during recompletion? Is the new heart destroyed? That would be a bummer, right? Or- and this seems more likely- the new heart AND the old heart join together in the recompletion, so every recompleted person has two hearts.
Furthermore, if this person is a Keyblade wielder, could they dual wield? We know Sora and Roxas could because of Ven's heart, would that work with essentially two of the same heart? For that matter, is a regrown heart functionally any different from the original? Like, is there a difference between the heart Axel grew as a Nobody and Lea's original heart?
Which leads me to my final nitpick: why isn't Axel freakin' dual-wielding now???