I am still playing Puzzle Quest (it's the #2 game I play after Picross right now), and the only thing I can tell you about that spell is that getting it is pretty luck-based. When I got it, I was lucky enough to get a Heroic Effort late, which really helped me out.
I agree with Phoenix Wright's score being one of the better ones on the DS. It really does help to drive the story, ESPECIALLY that overdrive beat that you're referring to. I don't find myself being as into playing when I'm not playing with sound.