The Magus Sisters

You must obtain Yojimbo and Anima before you can obtain the Magus Sisters. Check the Aeon side quest section for more information on how to obtain each of them.

The Magus Sisters are obtained as part of the Remiem Temple side quests and through challenging Belgemine during her last battle.

The Magus Sisters
Yuna battling the Magus Sister

Check out the Remiem Temple section for more information:

Remiem Temple