There is Bevelle and Zanarkand left. For me, Macalania was the most difficult to figure out. Bevelle isn't that hard to figure out, it just involves a lot of timing, and it's more difficult to do.

For getting the Destruction Sphere in every Cloister of Trials you do, you can unlock Anima, the aeon that Seymour has. This will also allow you to unlock the Magus Sister, a set of three aeons. They are kind of difficult to control, but once you learn how, they are really really powerful.