I recently started multiboxing, I went from dualboxing with keyclone to a 5 man hardware config. This boss was quite a challenge but after much trial and error I found a simple strategy to defeat him with your multibox team. This enemy is deadly for casters because of his casting speed debuff that stacks 4 times depending from how close you are to him. (50%/100%/150%/and up to 200%) He also has a bleed effect that stacks 4 times and I cant quite remember the damage something like 300hp per second, sometimes he will pull the entire group towards him just before activating the bleed effect. Besides all this he also sends a beacon to a targeted party member. You will see a raid icon and the targeted characters name. "Shirrak focuses his power on TOON1".....for example. The most effective strategy especially if the group consists of casters is to keep them as far from his spell casting debuff as possible, which im sure most of you know. Also, to have your main toon or tank run away from him when the bleed effect is stacked to either 3 or 4. My biggest problem was reaction time, controlling 5 toons is hard enough and now with movement necessary the battle can be a bit tough. The core of my strategy was to Initially keep my casters and healers at the minimal distance of the spell casting speed debuff. I set a movement key on my x-keys that would have all my character move backward...but this was taking too long for my healer and dps to get back in position. So I thought to myself why not have the tank run away from the group as well ass the group back up...at the very least it would give me more time to react. This strategy worked wonders for me, and I hope it helps.

From a set up perspective:

1. Bind strafe keys that will move all party members either left or right with the exception of your main focus/tank.

2. Repeat step 1 but with a down key to back up.

3. Have a way to make your main toon Independently move easily.

From a strategy perspective:

1. when the battle starts keep casters at farthest distance possible something like 30+ yards, and have your tank meet him where he stands in the back of the platform. (mines start out at the right side at the top of the stairs)

2. Dps him consistently and use any damage inhibiting buffs on your main focus as to not lose control of the battle early and get yourself situated. ( mines is a DK so Unbreakable Armor FTW)

3.Keep HOT's active, or plan your healing early to compensate for the 50% or 100% debuff. (use small spells if you have to Lesser Healing Wave, Flash of Light...etc.)

4.When Shirrak targets a character with the beacon (you will see the raid message) simply strafe your team to the opposite side....they will take no damage AT ALL!! (keep your tank in place not strafing him, and if you can cast an HOT while strafing do that)

5. Shirrak will then pull your team towards him (this was my toughest part of the battle)very simply back your support team up, while simoultaneously making your tank run away from the team (cast a HOT on your tank here if possible). (this is the key, you reduce the amount of time it takes your team to get situated dramatically) Furthermore you reduce the spell casting speed debuff as well as wipe away the stacks of the bleed effect.

I hope this is helpful and legible lol. if you need more help with this boss please pm me!!