Swing: 2312 - 6279 on Plate (level 80), capable of 9k+
Fel Lightning: A random target chain lightning that averages 4100+ Arcane Damage per target. It reportedly jumps 8 times. Range is unknown.
There are deactivated Protectors resting against the walls. These can be activated by Sunblade Scouts or traditional pulls. They are immune to stuns. A Scout needs only 15-25 yards to activate a Protector, so a lot of firepower needs to hit the Scout if the group intends to prevent activation.
Have the MT tank him with all of the melee behind the mob. Have the rest of the raid group up and spam chain heal. The Fel-lightning chains a set number of times and goes long distances, making spreading out impractical and reducing the effectiveness of chain heals.
Setup a location far from the group where the MT and melee group will fight. Have the remaining ranged DPS and Healers split into two groups, and try to keep healers even. Spread all three groups apart so that once all three spots are chosen, you form a triangle with each group at the vertices. Make sure to setup for max range between all groups. This will result in Fel Lightning affecting one group at a time. Assign AOE healers for each ranged group and target healers to handle the melee.