Okay...so I gotten Bahamut....with Squall's LionHeart combo and I gotten him...
then my goal is to get Eden and beat crap on Ultima Weapon.

Problem is...

Exactly, how to beat him?
I referred to so many walkthrough and 99% of them say to just cast Aura non-stop...some say to cast Aura - Invincible Moon - Aura - Triple, some say to cast Invincible Moon, summon Cerberus or cast Triple, Aura, Protect, Shell on everybody...some say Mighty Guard - Aura

So I my party order is...
Rinoa (lvl 7+), Quistis (lvl 100), Squall (lvl 100)

Rinoa: LV down, GF, Attack, Kamikaze
GF: Cactuar, Tonberry, Ifrit, Carbuncle

Quistis: GF, Item, Attack, Recover
GF: Leviathan, Shiva, Quezacotl, Pandemona

Squall: Mug, Magic, GF, Draw
P/S: With the most magic amounts then the others
GF: Diablos, Bahamut, Doomtrain, Cerberus, Alexander

So....I am so lost when it comes to fight Ultima Weapon because when the start of the battle, I forgot to cast Meltdown on him, then just cast Aura on everybody, Quistis use Mighty Guard while waiting for Squall's Limit Break then suddenly - Ultima Weapon: 2 sec - Meteor - 2 sec - Sword Swipe - 2 sec Gravija - 2 sec - Meteor - When Quistis is the only one standing - Light Pillar

.....T_T help please? *cookies for everyone*

Haven't fought him yet, but I'd suggest Aura on Squall and Lion Heart madness...

train the crap out of Rinoa, for real you'll waste a lot of time healing her.

lol okay x.x thanks guys. I just defeated Ultima Weapon but ermmm...wasted 1 Hero >_>" I used Hero on Squall and Squall did Lion heart madness, then Rinoa's Angelo Strike did the rest and >_> Ultima Weapon defeated....*sweat-drops*

Do things the lol'in way. STR at 255 plus Kamikaze = 50k damage. Have VIT at 255 on one of the remaining two characters and equip them with recover and revive. Plough the shit out of your foe with a combination of meltdown plus Zell's limit with his STR at 255. Easy peasy.