The Ry'Gorr Herbalist

Strategy
When you start the fight, 2 potions appear on the table : a red and a blue one. The red does 2% damage on the mob and takes 15% mana from the caster. The blue does 2% damage on the caster and gives 15% mana to the caster When a red potion is cast (a long cast), the boss will aggro a lot the caster. Make the tank cast alternatively the red then the blue potion. If you have a regen mana, just use the red one. There seems to be a death touch attack, not sure how this works or how to prevent it.