bahamut

ok i guess im just not that good at bonuses it took me a week and i still cant beat bahamut plz help

Okay here is what you do. First of all it depends when you do this. I done this after selecting my party on the GBA version. I had Cecil, Rosa, Rydia, Kain and Porom. Make sure Rosa and Porom have reflect. start out by casting Reflect on Rosa and Porom. Then Get Kain to jump. If you can, cast reflect on Cecil and Rydia but you might not have enough time. Mega Flare will be reflected back at Bahamut. If anyone died then revive them and cast reflect on them. Make sure to keep the reflect up. Get Cecil and kain to just attack. Have porom and Rosa revivie anyone or heal using items. Have rydia summon Leviathan. This is the strategy I used.

selecting your party?

On the GBA version. You can select your party after you get to a certain point.

oh

With the traditional party, have Rosa cast Wall/Reflect every turn, keeping herself Reflected is first priority. If you still have FuSoYa (which you probably don't), then have him help out here. Have Rydia summon Leviathan, Cecil attack, and Edge attack/use healing items. Kain should Jump when the timer reaches 2 so he can avoid MegaFlare.

If you still have Fusoya in your party, have him and Rosa cast Reflect when the Countdown begins. Have Edge throw Shurikens and Rydia cast her strongest Magic. Also, make sure your characters' levels are in the 50s

Does Bahamut even have any attacks other than Mega Flare? I mean, if Mega Flare is his only attack, you'll never lose the battle if you just have Rosa/Porom/FuSoYa cast Reflect on herself or himself. If you want to have Reflect cast on all party members by the time Bahamut casts Mega Flare, lower the battle speed. On the default speed, I was able to have Rosa and FuSoYa cast Reflect on everyone but Edge. On the slowest speed, you'll probably have enough time to cast Reflect on all your characters. After Mega Flare, revive any characters and recast Reflect if necessary.