I killed him last night as a 67 necromancer with a mercenary healer. I had a lot of buffs from the AFK pile in guild lobby but I believe what made it particularly easy was pulling him to the Teleport room you pass on your way to him. When clearing the way to pull him to the Teleport room keep in mind he paths around the right side (with door to your back looking at him across the water) when running to you.
Fhalst

Fabled Fungus Covered Scale Tunic
Robe of Living Fungus