Please help!

So, for the first time I made it to the final boss fight. Had 5 lives remaining when I arrived, I'm a level 46 Ghoul Sun Paladin.
http://te4.org/characters/192234/tome/d ... d64c5be14f
I'm down to two lives now, I'm just getting owned.

The two mages just burn me down, I usually don't last more than 5-10 turns. I think the best I've done is gotten one mage down 50%. Am I doing something wrong? How should a Sun Paladin be handling this fight?
If anyone can give me some advice to salvage this fight I'd appreciate it, this is the farthest I've ever got, I want to beat the game.
Also, how do you close the 4 portals? I can't seem to attack them. Thanks much!