When looking at everyone's focus concerning their stats/abilities, which Master would be the best for which char?
Sorry the board's dead, but here's an answer.
First off, there's no "best" because of the variability with how you build your characters. That being said, I'll address this in one of two scenarios.
If you want masters who play to your character's strengths:
Ryu: Bunyan, D'Lonzo, or maybe something more neutral like Bais
If you want my opinion:
Ryu: Giotto for quite some time (AP and HP help his dragon forms immensely), then switch over to someone like Hachio
Rei: Meryleep, then Bunyan when you're happy with his agility
Momo: Either Bunyan (offensive ideal), Emitai (healing ideal), or Deis for an awkward in-between
Peco: Giotto until AP's in the hundreds, then Fahl
Right now I have Ken (AKA Ryu :) ) with Bunyan, Garr with Fahl, Momo with D'Lonzo, and Nina with Mygas, and I'll put Rei with Meryleep when I get the chance.
Currently playing:Breath of Fire III/Solatorobo