Hmm....1 sec lemme grab my book........***
*ok got it, lemme take a look here. That's after seymours battle isnt it? hmm, yeah it is. Ok! enuff talking to myself, let's have a look here.
First off, the remedy's are for photon wings correct? I'm not sure you can get any near him, but if u have esuna on one of ur main characters you use then it works the same way.
I'll just give you a good strategy i used when fighting him:
Ok, so when u first start the fight, make sure to cast reflect on him, cuz later on he uses curaga, and is a big pain when he just cures more than you can even damage. hes also got the attack pattern of: photon wings, 2 regular attacks, and mana breath.
His photon wings casts sleep, silence, darkness and confusion on you. The real pain ones are darkness and sleep and confusion, not really silence unless ur using yuna or lulu.
Before you batle him, get ur aeons all into overdrive (you should have up to...shiva is it? maybe bahumat by now, cant remmeber). cuz when he starts getting low on hp, ur gonna wanna use ur aeons overdrive so its not such a pain to kill him.
Otherwise, just attack constantly, use esuna if you have it when he does photon wings, OR, just cure the status ailment that affects that character most. EX) if ur using auron, and hes got silence and darkness, obviously ur gonna cure the darkness, so dont worry bout the silence. and try equipping things that protect against these ailments if u can. and if that still don't work and u get wasted, maybe train in gagazet for a bit, cuz the monsters there should give fairly good xp. You've made it past seymour flux, so this shouldn't be tooo hard besides all the status [censored].
Hope this helps, can't really think of anything else to say. If i get any ideas ill let ya know. Good luck, and when u re-post, tell me who u r using as ur 3-4 main chars so i have an idea of what to suggest. Thanks, and good luck!