I would have a Dragon summon called '
Moontear'. I don't know why I would call it that, I just like the sound of it. She would be a huge purple/blue dragon with long wings. She is a powerful Aeon. She is weak against ice and water mainly.
Stats:
HP: 25000-50000
MP: 800
Attack: 250
Defense: 150
Magic: 135
Magic Defense: 100
Agility: 85
Evasion: 60
Accuracy: 100
Luck: 95 (I just used random numbers lol)
Abilities:
Dead Crescent: Attacks a single enemy with a lot of power and also casts a 'Death' spell. It doesn't always work though. It wouldn't work on bosses, that would make it too easy!
Angelic Kiss: Cures all party members 100%. Also revives any party members if they are KO'd
Overdrive:
Hell Blaster: Attacks several enemies with lots of fire balls, kind of like Ifrit in FFVIII except with more than one boulder.
Location of Moontear:
You can find her in one of the temples. You have to fight her and if you succeed, she will join your party. She isn't a secret Aeon. She's a very handy Aeon though.
Haha my mind can't think of anything better.