I beat him on my 5 pali tank team with ease. Couldn't get him down on my pali tank/disc priest/frost mage/ele shaman/dest warlock team, tried a dozen times all fails.

For my 5 pali tank team, I ignored all adds and just DPS'd him, even after he submerged I ignored adds and went right back to boss. When ever he cast the poison I would just spam follow and run in circles around him as they continued to DPS while moving. No wipes on him with this team yet.

The bind to account tank trinket is a very big help on all bosses. Seems the cooldown is short enough to use multiple times throughout the fight and the shield is awesome.