Thinking about it, I could see them bringing Asura for the next 8-man raid. Like Knights of the Round she isn't seen in many games (Most of her apperances being tied to IV) which would also give them some room to work with since people won't have quite as many pre-concieved notions about her in comparison to Bahamut and Alexander. In paticular she's the Queen of the Eidolons in IV, which could be worked into her having once been a ruler of Ala Mhigo or a previous civilization.

She also has three faces (Anger, Benevolence, and Joy) which easily could work into the naming conventions for the raids.