fanatics tower + life3 + moogle charm= super easy

Also why do you have Odin and not Raiden? Did you even bother beating the dragon in the ancient castle? (Walk like 5 or six steps down from the chair on the right in the throne room, and you'll hit a switch.) I'll let you figure it from there. Did you get the esper after cyans scenario? If you got gogo then you got locke I'm assuming. Also you've surely gotten Terra back, and Edgar. I'd go to jidoor next and check out owzers house. then hit the fanatics tower. Find Relm before you go to the fanatics tower though. Did you fight Bahumut yet? And once you have relm & strago go to thamsia. Did you go to the colleseum?

Lots of stuff to do, but since you have the airship you can go fight Kefka right now. Heck if you have even 6 people in your party split to groups of three and go for it, Kefka is a wuss. Make sure you have these items for an easy win though

Offering
Gem Box
Paladin Shield
Illumina (forget the esper man, that sword deals some heat and random pearl for 9999)
and Genji anything

Theres more stuff, but you don't want to make to end too easy like I did and get EVERYTHING good.