My ONLY problem really, are the beams. They are impossible to dodge with Terra. That's what usually kills me.
BTW, for Aqua, I recommend having 1 barrier surge, 5 thunder surges, and 2 curagas. That's how I did it.
Do you have once more and second chance? It comes in handy for the beams, you should probably equipt more curagas and constantly cure yourself as the beams hit you(He only used the beams twice with me though).