Molo'd this tonight on my 71 Shaman + my regular tank merc and the pet. I have about 250 AA's and 10.8k hp buffed. It took about 18 minutes.
I kept him slowed with Balance of Discord, kept Panther proc buffs up on the merc and my pet, and just healed it out. I had to use Staunch Recovery for a second bar of mana but only used about 50% of it, and I kept a Steadfast Servant up to keep my HP high. I basically just ate all of the AOE spin stuns. If you have some way to avoid them, that may make the fight considerably easier.

Lustrous Seaweed