Stay along wall to the right as you enter the room. Everyone stack up in far corner. AOE Prevent on incoming will help against the initial onslaught of damage. MT moves in and tanks in place. Melee DPS moves in.
Everyone crouch and walk mode as the mob has a fear AE.
Mob also has Vortex of Darkness, minor magic damage but heals mob (will see this later in zone). MA target and kills the 3 adds 1st then the named.