From what I've seen, I think Nomura really likes Axel because, well he's in both CoM and KH2. But that's a
mood point, and I may be wrong. I think he also likes Zexion though, because he gave him a good
cutscene for him and Roxas but then again, I'm probably wrong. But all those characters are a mood point,
all of them will be playable anyways.
EDIT: His favorite is Luxord, but I'm just saying he may like them some too.