Luxord's Regular Limit depends on whether you stop his card's shuffling on an X or the circle. If you get the circle he shoots a barrage of blasts at mid range for pretty large damage. Final Limit is two cards. If you get a circle you use his regular limit, two Xs and you fail, two spades nad you do a beefed up version of the regular limit.
Good, so you did know the rules.
My Luxord at the moment is just a heavy-focused spellcaster, but since I'm too **** lazy to synthesize them and whatnot, I only have several Thundagas, one Firaga, Curaga is garbage, but I put one or two on anyway, and the rest of the spaces are Fire, Fira, Thunder, Cure, Cura, and some Blizzara.
I think in total, I can cast ~40-60 spells, depending on what mission and whether or not heartless would be willing to drop Ethers and the like. Once I slot release the third panel (about halfway into it, maybe a little less), I'll focus on more magic stuff.