Sphere grid in Final Fantasy X?
I really don't understand how to use the sphere grid for Final Fantasy X. I'm fighting the Extractor, the one Rikku's supposed to be in, and I want Wakka and Tidus to have more HP. How do I do that? I tried playing around with it on Tidus's grid, but it keeps moving me back to this one space. I would also like to increase Wakka and Tidus's attack power. How do I do that?
Btw, I have a thunder ball for Wakka, so I know that will come in handy while fighting the Extractor, right?