An optional boss in the repository of Karazhan, this demon is a fun challenge and extra loot for your raid should you have time.
You may access his area by opening a bookcase in the Library wing and heading down the ramp - there's very few monsters in the way, namely imps and demons, but nothing too harsh for your raid.
Terestian is inside of a small room with a summoning circle in the center. His imp Kil'rek is beside him.
Imp Portal: Illhoof will open this portal 10 seconds into the fight letting imps pour out of it endlessly throughout the whole fight.
Demon Chains: Randomly, Illhoof will sacrifice someone and put them in the middle, unable to move and receiving shadow damage. All damage should focus on the chains that bind this person in the middle, or else Illhoof will regain a lot of HP from the damage he causes to the person. Healing is also needed. Once the chains are broken, you may resume fighting Illhoof
Shadowbolt: Shadowbolt damage to the first target in his hate list.
Amplify Flames: Increase damage taken by fire for 500 - used on his current target
Melee: ~2000 on cloth
Broken Pact: Makes Illhoof take 25% more damage, happens when Kil'Rek dies.
It is recommended you tank Illhoof and his imp where they stand, and the whole raid bunch up near them. There is no AoE to worry about.
Illhoof and his imp both aggro when you pull them. After 10 seconds, he will open a portal that will spawn imps steadily throughout the whole fight.
Ideally you should tank them both where they stand, so you are able to switch between the demon chains and Illhoof quickly, and that Kil'rek takes damage from the Area of Effect damage going on.
Set one tank on Illhoof, and one tank on his imp. The imp tank can be anywhere from a druid to a DPS warrior - he doesn't hit hard. What you must do is set all DPS on Illhoof, and switch it to the demon chains as soon as they spawn, and resume attacking Illhoof.
Imps will begin flooding the room. Have your warlocks throw seeds of corruption at Illhoof so they detonate instantly, damaging all imps nearby and Kil'Rek too. This way, Kil'rek will also be dying slowly thanks to the massive AoE damage going on.
Your warlocks will need healing as they AoE, as will mages who are coming to help with the AoE. Once Kil'rek dies, all damage on Illhoof will be increased twice until Kil'rek is resummoned a few moments later.
Seed of Corruption (Or a couple mages) are your best bet for this fight, if you don't have AoE damage available, you will be overrun by Imps.
If your warlock has Nether Protection, make sure your healers are ready to receive some fireballs from the imps as he will go immune everytime it procs, tossing the imps to the next in their aggro list, so while it will save the warlock, it may cause trouble to the healer.
Keep in mind the fireball damage is low, so Earth Shield and Power Word: Shield will help immensely keeping your warlock up!
Mages can Iceblock out of the chains quickly, Paladins can bubble out as well to save some time.
Breastplate of the Lightbinder
Plate - Chest
Equip: Increases healing done by spells and effects by up to 88.
Equip: Restores 13 mana per 5 sec.
Cincture of Will
Cloth - Waist
Equip: Increases healing done by spells and effects by up to 59.
Cord of Nature's Sustenance
Leather - Waist
Equip: Increases healing done by spells and effects by up to 64.
Equip: Restores 6 mana per 5 sec.
Mace - Main Hand
Speed 2.60159 - 296 Damage
(87.5 damage per second)
Socket Bonus: +3 Stamina
Equip: Improves critical strike rating by 24.
Equip: Increases attack power by 30.
Gilded Thorium Cloak
Requires Level 70
Equip: Increases defense rating by 24.
Girdle of the Prowler
Mail - Waist
Equip: Improves hit rating by 17.
Equip: Equip: Increases attack power by 48.
Equip: Restores 6 mana per 5 sec.
Cloth - Waist
Equip: Improves spell critical strike rating by 21.
Equip: Increases damage and healing done by magical spells and effects by up to 37.
Equip: Increases healing done by spells and effects by up to 44.
Shadowvine Cloak of Infusion
Equip: Restores 9 mana per 5 sec.
Staff - Two-Hand
Speed 3.00 132 - 271 Damage
(67.2 damage per second)
Equip: Improves hit rating by 25.
Equip: Increases attack power by 647 in Cat, Bear, Dire Bear, and Moonkin forms only.
The Lightning Capacitor
Equip: You gain an Electrical Charge each time you cause a damaging spell critical strike. When you reach 3 Electrical Charges, they will release, firing a Lightning Bolt at your current target for 694 to 806 damage.
Speed 1.4088 - 133 Damage
(78.9 damage per second)
Durability 285 / 285
Equip: Improves hit rating by 12.
Equip: Improves critical strike rating by 20.
Formula: Enchant Weapon - Soulfrost
Requires Enchanting (375)
Use: Learn how to permanently enchant a Melee Weapon to increase the damage done by your frost and shadow spells by up to 54.