The Magus Sisters
Location: Remiem Temple
To aquire The Magus Sisters, capture all the monsters on Mt. Gagazet and return to the monster arena to get the Blossom Crown. Acquire all the other aeons, including Yojimbo and Anima, and return to Remiem Temple in the calm lands. Challenge and defeat Belgemine's versions of your aeons. When you beat her version of Bahamut she will give you the Flower Scepter. Continue to defeat Yojimbo and Anima. Then move to the door in the back and unseal it with these two key items.
The Magus Sisters are three aeons in one summon... but they don't always listen to Yuna's verbal commands.
Unique Attacks: Camisade, Razzia, Passado
Overdrive: Delta Attack
Once the sisters are all in overdrive modes, a new command, "Combine Power!" appears. Choose it to unleash this powerful attack.