A couple of things that come in handy
Valor: Equip the weakest weapons so you can get allot of hits (i suggest the first one (i think it's called kingdom key) and the one winnie the pooh gives you (i think it's called sweet memories)) Then go to the land of dragons and start hitting the horse men things because they drop lots of drive balls so you can stay in drive longer YAY.
Wisdom: Equip the best sword you have (its better to have more magic power than strength) and go to the world that never was (Before you go in the castle) because theres practically infinate heartless there (its much easier to kill them if you use magnega).
Master: Again equip your best weapon but this time get a good strength weapon and a good magic power one then go to the land of dragons and kill the horse men again because to get master levels up you need to get drive balls.
Final: to obtain this form you must do about 50-100 drives, then equip best weapons and go to the world that never was (castle) because theres loads of nobodys (i recommend using the drive at the place were there is all the weak nobodys because they die quiker also it comes in handy to make loads of the best drive recoverys (the ones that fill 3 bars) I had 55 of them and got to level 7 final.
You should know that this is the strongest boss in the game. You should get to level 85 and have the final wapon and Soras inventory of Hi-potions( Elixers would be better) to even have a chance (unless your really good you could maybe beat him at level 75, I beat him the first time level 90 then I beat him again level 80.
Now when you start the battle press triangle repeatedly, and always be prepared to press triangle, also run away from him when he floats in the air because he'll do a spell called "Sin harvest" (it lowers your life down to 1 and magic down to 0) then quickly use your item before he comes after you, also run away from him using the fire pillars because they will draw you in, and finally when he casts meteo just run and try and save yourself theres no real way to avoid it (just becarefull)
Note: he will only cast meteo when he gets down to his last bar of life, and you can't use drives throghout the battle :(
Good luck and hope this helps.
Added by: worst ffx playa .. Jun 29th 2007, ID#27043