I didnt even need a SEN in this fight, I used Snow(COM) Light(RAV) and Vanille(RAV) and then when needed all i did was switch Vanille to Medic and keep everyone else the same, also what you can do is if needed switch to Combat Clinic (SEN+MED+MED) before the attack goes if you really can hit him hard enough, also yes, make sure your buffed helps alot