Get all yer aeons maxed to over drive before fight and then fight it for you can use overdrive then attack and if you can get the players to their overdrives to for they can use it...when he starts sparking i think he's getting ready to use the move which is almost impossible to live through but he should be low on HP when he does that so just try and unleash all yer overdrives and save yer strongest Aeons overdrive for last