how do you beat sanctuary keeper

I tried to beat sanctuary keeper millions of times but he keeps killing me and my aeons bloody *******. I dont know how to beat him

In my new game i just beat him today...easily. Anywhoo i first used armor break with auron then started attacking! auron had about 65 strength then which isn't very good. Tidus also had about 55 strength. he uses photon wings i think it is...i had some armor with some wards so it wasnt too bad i just used an al bhed potion with rikku. i kept auron and tidus attacking the whole time. auron doing 8000-9999 and tidus doing good amounts also. consdiering i was so strong and he had 40000 hp he died quickly and never used curaga. in my old game i had some trouble though. Use auron, tidus, and yuna/rikku/wakka/lulu lol. auron using armor break then attack like before. considering your not super strong just keep up the attacks and use overdirves. when he uses phton wings use al bhed potion or esuna and heal. he will probally use mana breath. considering you don't have enough HP to survive revive the fallen character. keep up attacks and overdrives. use aeon overdrives also but dont summon an aeon if it doesnt have an overdrive unless your using grand summon. after hurting about 10000 use reflect on him so he doesnt use curaga. just keep at it and hopefully he will die soon.

I did what 787b but first cast bio, then reflect, O and don't forget Hastega that will come in handy, then once poisoned, just drill its Hp out!

Lol, you don't need to do that much, Reflect on him then Aeons Overdrives, 4 aeons should do 9999 and Bahamut 20,000. So 1 bahamut Mega Flare plus 2 aeons overdrives of 9,999 and 1 strike from Tidus would kill him, You don't need hastega and all those rubbish on this rubbish boss

It's not a cheapp way, weak characters rely on Aeon, strong characters rely on quick hit, but I doubt you'd get strong when ur up to S.Keeper, hehe~