I beat Braska Final Aeons both form with only aeons.

Bahamut, Anima, Ifrit, Valefor, Shiva, Ixion is used to finish first form.

Yojimbo and Magus Sisters is used to beat the second form.

Just to try Zanmato but he do Wakizashi, then he's death after a few turns.

Magus Sisters can handle theirself well, Auto-Life is what I have Cindy to uses, Sandy use supportive magic and Mindy with her magic. They are protected against status and that hell good. Moreover, Jecht Overdrives does only 2000 damage which is 1/4 of my Cindy healing damage. I beat them with this Three Sisters.