He's easy..
Just block his hits then hit back a little n stop.
When he shoot balls just simply spam the dodge L+R+ analog direction. do this till he is at the 3 pillar above. switch weapon n hit one of them.
The 2nd or 3rd phase he should be casting area of effect skill. Just stay away from him until his last one that casting at the middle of the ship. Then just jump at the right time to dodge it and go near him to deliver some dmg until he's back to the pillar again.
If u find urself hard in one of the situation.. Just spend the wrath (R+Triangle) to dodge.
I think I miss a phase. Any1 can correct me?

This game is cool. Graphic is really nice.. maximizing the psp's engine. If only it can last longer... -.-