Yeah, that's it. If you have auto-phoenix, you can get 99 S. levels in one battle.

Also, sorry for going off-topic, but I didn't want to make another thread.

When should I fight Sin (Where he has an overdrive meter)? Atm, I have Auron going through Wakka's sphere grid, and Tidus going through Auron's. The rest (Lulu/Yuna/Wakka/Rikku) aren't done their sphere grids yet (Although Yuna is almost done.)

So, should I put Wakka through Tidus' sphere grid, and then level up yuna/rikku/lulu to put them through someone else's sphere grid (I don't know who...); and THEN fight Sin?