Just use sableye for joey. then spam taunt->knock off... until rattata dies. then use taunt when joey send regigigas or when taunts effect ends. don't worry, sableye has prankster (while regigigas is in taunt, knock off leftovers then will-o-wisp regigigas. when its done, do pain split if regigigas' hp is higher than sableye's max hp, otherwise spam knock off)