well u can easily equip urself with Stoneproof/ward armour (u shud have loads by now OR u can buy it OR make/customize it real easily) and that shud solve alot of probs. <img src="/images/graemlins/smile.gif" alt="" />
but u really shouldn't have many probs with taking HP from this guy, if ur not strong enough u REALLY need to level up some
if u really can't be bothered, use overdrives. wakka's attack reels are wicked (the best OD in the game) and Rikku' mixes are extremely useful if ur physical damage isn't too good. check a FAQ (like GameFAQs) for info on mixes and how to make them in battle.
remember all elements cause more damage to him than normal <img src="/images/graemlins/smile.gif" alt="" />