World of Warcraft Legion Emerald Nightmare: Il'gynoth Guide

Check this guide for info on defeating Il'gynoth in the Emerald Nightmare raid in Legion!

Il'gynoth, Heart of Corruption is one of the 4 bosses you can choose to fight after Nythendra in the Emerald Nightmare raid. This boss is a mass of corruption that seeps into the ground to summon many horrors for your raid to face.

It is mostly an enemy management fight and has a phase where you can deal damage to the boss.

I'll go over everything you need to beat this boss.

This guide will go over defeating Il'gynoth in the Emerald Nightmare raid in Legion including:

  • Fight Basics - The important things you need to know, no matter what role, and how the fight works.
  • Role Orders - What each role, DPS, tank, and heals, needs to do in this fight.

Fight Basics

  • The boss has a 99% damage reduction buff, so don't bother attacking while you are outside.
Phase 1 - The Ruined Ground

This is the main phase of the fight and the one that takes the most effort.

Everyone will be outside and will see an Eye. This is the outside of the boss and cannot be damage by normal means.

There are multiple enemies, mostly tentacles, that you must kill while you wait to go inside.

  • Tanks should take Dominator Tentacles because of Rupturing Roar and Nightmarish Fury.
    • Rupturing Roar deals damage to all players and only happens when nobody is in melee range.
    • Nightmarish Fury deals heavy damage on its main target, so this should be a tank.
  • The Eye of Il'gynoth will use Nightmare Gaze, which deals damage on someone at random.

Everyone should avoid the Spew of Corruption ability from the Corruptor Tentacles

  • If hit, you will take damage and leave a pool of Nightmare Corruption on the ground every 2 seconds for 10 seconds.
    • If you get this, run away to a safe area in the room, away from the Eye and allies.

Nightmare Ichors are blobs that spawn every time you kill one of the other enemies. 

  • These fixate on random players and should be taken next to the Eye.
  • When you kill them, they explode in the area you killed them in and deal damage to the Eye if in range.

When the Eye takes enough damage, the pathway inside to the heart will open and start phase 2.

Phase 2 - Heart of Corruption

wow legion il'gynoth heart

This is when you can go inside and damage the heart directly. Killing the heart wins the fight.

This is where your raid should use heroism/bloodlust.

  • During this phase the heart will use Dark Reconstitution to regrow the eye.
    • This lasts 50 seconds and kills anyone who remains inside after the timer is up.
  • Players should stand 11 yards away from those affected by Cursed Blood.
    • Cursed Blood deals damage to the target every 2 seconds for 8 seconds and explodes at the end to deal damage to anyone within 11 yards of the target
  • If there are any Nightmare Ichors still alive after the eye is destroyed, kill them before they can enter the heart chamber.
    • Ichors deal damage to all players if they get inside.

Make sure you get out in time, then it is repeat phase 1 until you can go back inside.

Add/Enemy Priority 

While outside, some adds should be focused on above others. I'll list the order you should kill them in if there are multiples.

  • Deathglare Tentacles - They will constantly damage someone, but you can also interrupt its Mind Flay.
  • Corruptor Tentacles - They spew corruption, which can get out of hand if not killed quickly.
  • Nightmare Ichors - This is how you can get inside to damage the boss, plus they will constantly damage people with Touch of Corruption
    • Touch of Corruption is a DOT (Damage Over Time) that lasts for up to 40 seconds and stacks.
  • Dominator Tentacles - These shouldn't be much of an issue as long as a tank takes it and everyone stays out of line with the tank.
    • The damage it deals on the tank can get intense if left up too long.
  • Nightmare Horror - This is the smallest threat, but can still cause problems if not properly managed.
    • They will periodically leave pools of Nightmare Corruption underneath them.

wow legion il'gynoth nightmare horror

Role Orders

  • Tank the Dominator Tentacles and Nightmare Horrors when they spawn.
  • Swap on Nightmare Horrors when you have 2 stacks of the Eye of Fate debuff because you will start to take high damage from the Nightmare Horror.
  • Be sure to keep the Nightmare Horrors away from the raid and move whenever a new pool is created.
  • Use cooldowns when teh Dominator Tentacles use Nightmarish Fury.
  • Dispel Touch of Corruption from affected target when the damage becomes too much.
  • Be ready for more healing when Nightmarish Fury or Eye of Fate happens.
    • Also, lookout for anyone standing in corruption or near the Ichors when they explode.
  • Never attack the Eye and follow the above Add/enemy priority list.
  • Interrupt Mind Flay from the Deathglare Tentacles.
  • Always take the  Nightmare Ichors near the eye, unless you have corruption on you.

That's it for my guide on defeating Il'gynoth in the Emerald Nightmare raid in Legion. Let me know if you have any questions!

Guide Editor

After gaming for 25 years, Synzer leveraged his vast knowledge of RPGs and MMOs into a job as a games journalist, covering the games he loves. Five years later, he's still writing about Kingdom Hearts, Pokemon, and Knights of the Old Republic. Synzer has a bachelor's degree in English and creative writing. You can see him in action on his YouTube channel ( and Twitch (

Published Sep. 29th 2016

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