Terestian Illhoof and Kil'rek - Karazhan

Terestian Illhoof and Kil'rek are an optional (but advisable) set of bosses in Kara. This duo can give unwary raiders a few problems, in most part because of sacrifice but in several cases because of overwhelming numbers of imps.

There are fortunately a few simple tactics that can make Illhoof not just easy, but incredibly simple. You will however need a warlock!

First though here is the stats and spells for this demonic duo and their pets.

Terestian

• Basic Melee - Illhoof hits for around 1800 damage on a tank, 3-4k on DPS.
• Shadow Bolt - Illhoof fires a 4k damage Shadow Bolt at the highest target on the aggro list.
• Sacrifice - A random character is summoned to the centre of the room and is paralyzed, suffering 1,500 shadow damage per second until the chains are destroyed. While the chains are up, Illhoof is healed for 3k hp per second. The chains have roughly 13k health and can be removed with Ice Block or Divine Shield. It will not be cast on the main tank. A druid can use barkskin while chained to reduce damage taken.
• Berserk - After 10 minutes, Illhoof goes berserk, spamming high-damage Shadow Bolt Volleys on the entire raid every few seconds.

Kil'rek

• Basic Melee - 2,000 on cloth.
• Amplify Flames - Undispellable debuff that increases fire damage taken by 500.
• Broken Pact - Debuffs Illhoof on death, making him take 25% more damage until Kil'rek respawns (~45 seconds after death).

Summoned Imps

• Basic Melee - Approximately 400, rarely used.
• Firebolt - 200 fire damage, up to 700 if Amplify Flames is on the target Cast very quickly.

Now onto the tactics.

The most important thing about this fight is the sacrifice. It is important that your DPS jumps straight onto attacking the chains the instant a person is sacrificed, when this happens the sacrificed player will be teleported to the middle of the room.

Because the chains heal Illhoof it is imperative these are downed ASAP, a macro such as
/target demon chains

or, if you fancy something more spiffy,

/cleartarget
/target Demon Chains
/stopmacro [nodead, harm]
/target Kil'rek
/stopmacro [nodead, harm]
/target Terestian Illhoo

Will help significantly in selecting the correct target.

Ten seconds after the fight starts Illhoof will open two portals from which a constant stream of Imps will appear. The best way of dealing with these is for a warlock, or if possible two warlocks to spam seed of corruption, this is incredibly effective at taking out the imps. If you do not have a warlock mages AoE or a rogue single target speedily taking them down can also work.

Killing Kil'rek is simply a matter of choice for your raid. If you can take him down in under 20 seconds it is advisable, anything more and you would probably be better off leaving him on the off tank. The befit of getting Kil'rek down is a 45 second debuff on Illhoof which increases his damage taken by 25%, quite a bonus!

It is preferable to fight this with two tanks, the main tank on Illhoof and the offtank keeping agro off the healers when new mobs get agro'd by the Warlocks seed of corruption. The tank should keep Illhoof between the two imp portals to maximise damage from the AoE effects used.

One healer (Paladins are best for this) should be assigned to instantly keep the sacrificed player up, other healing classes should put up HoT's to help mitigate the damage though

DPS go all out on this one, If you are killing Kil'rek wait until Illhoof receives the debuff before using cooldowns.

All in all Illhoof and Kil'rek are a fairly easy takedown, raids new to this boss may find it takes a couple of tries due to this battle becoming rather chaotic at times, but once the basics have been learnt you will breeze through Terestian Illhoof.