Light/Hope/Vanille. Start MED/MED/MED to eat his initial Merciless Judgment and then switch to MED/SYN/SAB. Buff up and make sure Vanille lands Poison! When Poison is up and you're decently buffed, just tank him in MED/MED/MED, reapplying Poison as necessary. Put some Cherub's Crowns on your main character and others if necessary. Should be a fairly quick and painless fight.
Second form: start COM/SYN/SAB => RAV/SYN/SAB until you have Haste on all of you and maybe a handful of debuffs on him. After this, RAV/RAV/RAV and stagger him really quickly. As soon as he is staggered, Army of One and zerg and he should die on the first stagger.