So what I'm getting out of this game is that each character has one summon assiciated with them? Interesting. So it's not like 10 or 9 where only Yuna can summon, or Garnett & Eiko have unique summons to one-another, and not like most other games where everybody can summon every creature? This is interesting.

It makes me wonder about a new idea. VIII, VI, X, and several other games had very unique places for Summons in the storyline, usually as some sort of ancient being who had died, but no game has ever made the playable characters the summoned monsters themselves. Imagine if you had some effinity for fire and could summon your rage to transform yourself into Ifrit. Interesting idea, although that's not exactly what's going on in XIII. Still it would make for an interesting take in the battle system. You may have a magic limit break seperate from the physical one that allows you to transform.