by Ackthal - Thanks to Escara for corrections :)
Kanrethad is the final encounter of the quest line for warlocks to obtain green fire spell-effects. At the time of this post, he is one of the hardest solo encounters to date; from experience I’d say it’s more difficult than the benediction/anathema event. I’ve also been told it’s more difficult than the solo encounter to obtain Teragosa.
There are many ways to approach each facet of the encounter and this guide contains what I have found to work best. It is by no means an all-inclusive guide but I will try to shed light on some of the more important factors of the encounter.
You can also watch my video of the fight at: http://www.youtube.com/watch?v=5IcodMZVDcY
All three specs work for this encounter but I have found that destruction is the easiest to pull it off with and it is what I’ll be using in this guide. With destruction you have only one DoT to track and it has one of the most basic spell rotations. This will allow you to mindlessly cast while dedicating almost all of your attention to the mechanics of the fight.
Destruction contains some very nice burst (both AOE and single target), which will be Important during the Imp and Felhunter phases (covered in detail later). The ability Ember Tap can also be useful when low on HP.
Icyveins guide to Destruction Warlocks: http://www.icy-veins.com/destruction-warlock-wow-pve-dps-guide
Soul Leach: Provides you with 10% of your damage as an absorption effect, a nice passive ability that will add a lot of points to your overall HP pool during the fight.
Shadowfury: Used during the Imp and Felhunter phase to reduce damage received.
Sacrificial Pact: Used to soak Chaos Bolt or other incoming damage.
Unbound Will: Used to dispel yourself when you can’t use your Pit Lord dispel.
Grimoire of Sacrifice: You will be enslaving a Pit Lord the entire encounter so you will not be able to have one of your own pets out, might as well pick up the extra damage and regeneration. Be sure to sacrifice the Imp for Cauterize Master, which can be used in conjuncture with the Pit Lord Fel Flame dispel and Unbound Will (more on this later).
Kil’jaeden’s Cunning: There is a lot of movement in this encounter and being able to cast while doing so will dramatically increase your DPS.
Glyph of Siphon Life: Provides passive HP regeneration.
Glyph of Healthstone: 100% more HP from your healthstone, nice in clutch situations.
Glyph of Ember Tap: Provides 5% extra healing from your ember tap ability, but over 10 seconds. You may choose to not use this glyph if you will be relying on a quick injection of hp (preparing for incoming Chaos Bolt).
Glyph of Dark Soul: If you have T14 set bonus Dark Soul will be off cool down most of the fight since you will be saving it for the Felhunter phase, this is where this glyph will benefit you most. You may feel that you can manage the timing of the cooldown to be able to use it in-between each Felhunter phase (I like to use it a second time during each cycle in-between Doomguard and Imp phases), if so, don’t use this glyph, but be warned that having it ready for the Felhunter phase is a MUST.
Glyph of Enslave Demon**: You need to use this for this encounter as the Pit Lord will
Charge you and stun for 5 seconds if you don’t get this cast off fast enough. You will casting Enslave Demon more than once throughout the fight.
Glyph of Gateway Attunement** (or alternatively a Gateway Control Stone): Allows you to walk through your demonic gateway to use it, rather than having to click it. Since using the gateway as much as possible is a necessity in this fight, this glyph (or the stone) is a must.
Curse of Ultimate Doom: 2 second cast debuff- 500 million damage after 7 minutes. This is Blizzard’s way of capping the time limit on the fight. It can be easily dealt with by using a Purification Potion to remove it once, potentially extending the time to 14 minutes.
Excruciating Agony: A slow ticking DoT that will build up in damage as it stays on you (must be dispelled).
Seed of Terrible Destruction: A debuff that will expire after 15 seconds, randomly applying one of three effects.
1.) Annoying Imp: This is an undispelable debuff, an Imp will latch on to you and interrupts casting and stops movement every 2-3 seconds.
2.) Void Zone: Knocks you back about 20 yards and generates a void circle about 10 yards in diameter at point of knockback. If you step into this void circle it will suck you in and trap you while doing continual damage, eventually killing you.
3.) Backfire: Debuff that provides a 25% damage increase.