Frustrated over the big O.

[Silent Warrior]

So, I'm at the final boss. I think. I thought so when I hit the first stage (thought He was the biggest push-over since Necron - the joke's on me...) too, but mister I've-got-six-million-HP-and-a-steady-stream-of-2500+-healing-every-two-or-three-seconds keeps busting me up. Has done so for the past 6-7 hours. So I'm frustrated! Grr! (I'm also avoiding names, in case someone hasn't beaten him yet.)

I think my party is up to snuff, though I haven't really been grinding/CP-farming. (Bored... ) I wouldn't mind suggestions, though, in case I've missed something. HPs with Lightning, Fang and Vanille are all 7000+, I don't remember exact numbers, but I'm sure the main offensive stat is 1000+ (1400+ for Lightning's Strength?), second tier weaponry (Lightning's and Fang's at lv 30+, Vanille's at 15). Fang as Commando deals about 2000-8000 damage with each hit, depending on form and status - Lightning as Ravager is a bit less exciting. I manage to Stagger the light form on occasion, but I have to use two Medics for the dark and opposite forms. Maybe not ideal, but progress is steady, if slow.
I've learned that Cherub's Crowns are Good For You - maybe I'll upgrade them, now that I've had to quit for now, having to start from a save point next time around - and that you should bloody well not get poisoned. Other debuffs are manageable. I've also learned that Renew and Dispelga are glorious allies.

... So, Relentless Assault, Discretion, Diversity, Aggression, Tireless Charge, maybe Scouting Party for the dark form (might have to make that Med/Sab/Med (Med/Sab/Sab?)), do I need anything else? Is there something further I need to keep in mind? Does it seem like I've missed anything at all? I'm starting to think highly of the Synergist role - only way I could get past the Proudclad - but with all those debuffs flying around during the dark form, necessitating Dispelga now and then...