Quote Originally Posted by Wolf Kanno View Post
I get the odd feeling Bahamut might be special... I'm still in the belief all the summons will combine to form Voltr... I mean Bahamut.
That's be interesting. Special Summons by combining the ones in your party. Like Dual and Triple Techs from Chrono Trigger

Siren is probably for an unconfirmed character. I wouldn't be surprised if some fan favorite summons are also villain exclusives now.
That sounds like fun too. You don't fight enough summoners in these games.