I've just managed to complete the challenge as a 900 iLvL Holy paladin. It takes approximately 15 minutes to finish all the stages. The challenge is relatively simple (at least for my class) once you know exactly what is going on. Here is a brief overview.
You'll be completing the challenge as a group of four: A tank, a melee DPS, a ranged DPS and yourself. Despite the numerous interruptable casts, the other members of your group will not interrupt, stun or try to help you in any way. It is up to you to essentially deal with all mechanics yourself.
The The fight consists of 7 stages, but really only 4 main parts. These are:
Part 1: Dealing with Adds
For the first part, waves of mobs will come at you until you have killed all of the mobs in the room. There are three types:
1.
Corrupted Risen Arbalest (Archer)
2.
Corrupted Risen Mage (Mage)
3.
Corrupted Risen Soldier (Rogue)
The
Arbalests will jump around the room and fire at random group members dealing moderate damage. They will also cast
Mana String at you (5 second cast time) which will deal damage and drain mana from the first enemy target it hits. Make sure there is a party member between you and the mob when the cast finishes.
The
Mages will chain cast
Arcane Blitz. Each time they successfully cast the spell, they will deal 50% more damage for 5 seconds (stacking). This will quickly be fatal for your group. If you stun these mobs at around 50%, you should avoid having them kill anyone.
The
Soldiers have two abilities. They will cast
Knife Dance (a group wide AoE for moderate damage) and a fixate. You can kite them during fixate, but it isn't always even needed.
These mobs will come at you in 5 waves. These are:
Wave 1:
Archer
Wave 2:
Mage,
Archer
Wave 3:
Mage,
Warrior
Wave 4:
Mage, 2 x
Warrior
Wave 5:
Mage,
Archer,
Warrior
From wave two onward, you should try to CC either an
Archer or
Warrior. Your party will focus on the
Mage first, and have no problems breaking your crowd control. Deal with the remaining mobs as discussed above. Try to save healing cooldowns for waves 4 and 5, as they are quite intense. Ensure that you stun or interrupt the
Mage so that its stacking damage buff falls off.
You do not need to worry about saving cooldowns, you can wait for as long as you want after this stage is done for your cooldowns to come back up (drums included).
Part 2: Saving your Group Members
After you finish stage 1, the boss will take your followers and you will have 6 minutes to reach the end of a series of rooms before they die. You need to do this part alone. This involves killing mobs and keeping yourself alive.
Room 1: 6
Flickering Eyes will spawn with 600k health each. Every time you kill one, you will be dealt massive damage. Make sure you top yourself off after you kill each add.
Room 2: You will have to kill one
Felspite Dominator (6.2m HP) and two
Fel Bat Pups. They don't hit too hard. I used DPS cooldowns here.
Room 3: Contains one
Panicked Soul and three
Damaged Souls. Dispel the
Panicked Soul and heal the
Damaged Souls to full health. If the
Damaged Souls die, they will spawn enemies with a large amount of health that you have to kill (which may make it difficult to beat the timer). After you do this, there is one
Corrupted Risen Arbalest at the top of the stairs you must kill (the same type as at the beginning of the instance). Try to CC him when he casts
Mana String on you as you will not have anyone to soak it for you.
Room 4: Take your time moving through this room trying to avoid the
Unstable Fel Orbs. If one starts channeling on you, kill it and heal yourself before moving again.
Room 5: Contains one
Dread Corruptor and three
Flickering Eyes. Kill the
Dread Corruptor fast then kill the
Flickering Eyes one at a time when you are full health (they will explode as they did earlier).
When you kill the mobs in the last room, you will get a break to drink and wait for your cooldowns to come back up.
Part 3: Healing the Souls
You now have your allies back, but they will start fighting each other after some RP. You can't let them die for this whole phase and they will require constant attention. In addition to this, the boss will spawn waves of three spirits (one
Damaged Archer,
Damaged Mage and
Damaged Soldier) every 20 or so seconds or so which will move towards him. If they reach him, they will be absorbed. To stop him absorbing spirits, heal them to full health before they reach him. The phase ends when you fully heal 8 spirits.
When you heal the 8th spirit, the boss will give you a short break to drink and then make you fight every spirit you did not heal. For example, if two
Damaged Mages were not healed to full and were absorbed by the boss, he will spawn two
Corrupted Risen Mages (the same as in Stage 1). For this reason, you should prioritise the adds you heal in each wave. I would recommend healing the
Damaged Mage first, then the
Damaged Archer, then finally the
Damaged Soldier.
This phase is very healing intensive and likely the hardest part of the challenge. As you don't want to have the boss absorb the adds, you want to manage your cooldowns to maximise how many you can heal in each wave. I used drums right when the first set came out along with a small cooldown and prolonged power potion to heal all of the adds in the first wave. I then used all my remaining cooldowns on the second wave to heal all three again. On the third wave, I was only able to fully heal one spirit. On the fourth wave I healed the final spirit, resulting in the boss spawning two adds (one Archer and one Soldier) at me.
After you finish this part, you will have a small break to drink before you fight the boss (but you do not get an opportunity to wait for cooldowns).
Part 4: Killing the Boss
Lord Erdris Thorn himself is very simple. He has two abilities. For his first ability, he will jump on you and place a large fel pool on the ground. For his second ability, he will place
Ignite Soul (where you deal damage to your party equal to your health when it expires). Move into the pool and get to about 20% each time this is cast.
Make sure you make good use of the space in your room and you will have no issues. The healing requirement in this phase is a joke and is by far the easiest part of the challenge.