Background

Once, this was a sacred burial site for the Night Elves, but the Legion has twisted these grounds with the Engine Souls. This foul machine draws upon the energy of the dead, twisting them into abominations. Due to this corruption, these tormented spirits have become monstrosities, looking to feed on any who descend into the tomb´s depths.

Overview

This fight is based on two realms, on the same platform, the living, and the dead.
Players that fight on the living realm can see players as shadows on the dead realm and vice versa.
Each realm has one boss and realm specific adds that spawn in waves.
There are wells alongside of the platform in which you can swap realm before and even during the fight.
The raid needs to be divided in two groups, one for each realm, with a tank, healers and dps in each realm. If no players are in a realm, the boss will do high pulsating raid AoE damage that eventually wipes the raid.
There are mechanics that can affect both realms so positioning in each Realm is very important.
The bosses share health and at 30% (not in LFR), the Desolate Host comes out from the Engine of Souls, that you fight in living realm. During the last 30%, you will fight the same boss in Spirit Realm and the Desolate Host and Engine of Souls in living realm.

Positioning

The easiest way to do this encounter is that you will only have ranged players in Spirit Realm.

Living Realm (Corporeal Realm)

Tank
Stand on top middle and tank boss.
Pull the adds that spawns in the center to you and tank all adds on top of boss.
Face all ads away from raid so that they face the boss.

Melee
Stand on the right side of the adds.

Ranged
Stand on the right bottom side of the platform.
Stand at max range from boss

Dead Realm (Spirit Realm)

Tank
Stand on the upper side of boss. Boss doesn’t move and is positioned on the top left side of the platform.
Pull the priestess adds to you and tank them on top of boss.
The small soul adds cannot be tanked.

Ranged
Stand on bottom left side of the platform.
Stand at max range from boss.

Abilities and Tactics

When no players are in the current realm, the boss in that realm will do deadly ticking damage that also increases the damage the boss does by 25% for 12 seconds (and stacks). Boss bosses in each realm has this ability (Quietus).

Heroic Mode: If any player/add in the Spirit Realm are within 8 yards of a player/add in the Living realm, it inflicts 315k Shadow damage periodically.

General Raid tactic

Have only ranged players in Spirit Realm.
Living Realm can be mixed melee/ranged.
1 tank in each Realm
Healers divided between realms.

The Living Realm (Corporeal Realm)

In this realm, you will fight the Engine of Souls and 2 types adds that spawns in waves.
All adds are mobile and the boss is stationary.

Boss: Engine of Souls
Adds: Templars and Bonewardens

BOSS – ENGINE OF SOULS

Bone Shards

Boss shoots Bone shards on tank that does 100% weapon damage.

Collapsing Fissure

Shocks that creates a Collapsing Fissure on random location for 1.5 min.
Players standing within the Collapsing fissure takes Shadow damage every 1 sec.

Tactic: Collapsing Fissure

Since these can come on different locations, it can screw up the positioning.
Move away from the fissures on the ground and stick to the positioning as much as possible.
These fissures will be on the ground for a long time before they are gone.

Tormented Cries

Boss targets a random player.
After some seconds it will shoot the player with a cone shaped purple magic.
This does very high shadow damage.
If the targeted player is standing on a purple cone shaped Tormented Cries, it will increase the shadow damage by 300% when getting hit.
If a nontargeted player stands on the purple shape, it will do damage every second.

Tactics Tormented Cries

Run to the right side and wait until boss shoots it at you, then run back to your position.

Always start furthest away and place the Tormented Cries there, then place the next one next to it and so on.

The Tormented Cries will be on the ground for a long time before they are gone.

ADD - REANIMATED TEMPLAR

This ad has 1 ability in normal mode and 2 abilities on heroic mode, and can be tanked.

Rupturing Slam

Slams the ground which creates ruptures that travel around.
Players getting hit by it will take Physical damage and knocked back.

Bonecage Armor (Heroic)

At 50% health, the add takes 75% dmg reduction for 1 min.
The shield breaks if the add gets hit by Shattering Scream

Tactic: Bonecage Armor (Heroic)

When the Templar has 50% hp and Bonecage armor, Players on the Spirit Realm need to stand on the Templars when they have 5 stacks of the Shattering Scream debuff they get from the priestess add in spirit realm.

The Dead Realm (Spirit realm)

In this realm, you will fight the Engine of Souls and 2 types adds that spawns in waves.
All adds are mobile and the boss is stationary.

BOSS – SOUL QUEEN DEJAHNA

Crush Mind

Boss shoots the tank with high shadow damage.
This leaves a debuff that increases damage taken by Crush Mind by 5% and stacks.

Tactic: Crush Mind

Tanks
Tank swap should not be needed here if handled proper.
Everyone in this realm should help interrupt the Crush Mind.
Beware of using some defensive cooldowns if your stack is too high.
There will be a pause for 1 min when the boss does wailing soul. This is a good opportunity to get some interrupt cooldowns back and eventually remove the stacking debuff that lasts for 1.5 min.

Raid
This can be interrupted and must be interrupted as much as possible.

Soulbind

Boss binds the soul of two players together, one from each realm.
This does high shadow damage to players within 10 yards every 2 seconds.

Tactic: Soulbind

Targeted players meet up at star, when debuff is gone, players go back to their positions.
You can see when a player is targeted because they will have a blinking flashing light around their characters.

New note: Star can be placed further inside the platform (in the center).

Wailing Souls

Boss does a channel of shadow damage every 2 seconds for 1 min.

Tactic: Wailing Souls

Tank and Healer stay in living realm.
Dps, switch realm and help killing the adds on living realm. Switch back when boss is done casting wailing Souls.

Wither

Boss puts a debuff on random players in the spirit realm.
This debuff does 285k shadow damage every 3 sec for 1 min, and will also increase damage taken when boss does Wailing Souls.

ADD - FALLEN PRIESTESS

This add has 2 abilities

Shattering Scream

Debuff on a random player that does damage every 1.5 sec for 7.5 sec (5 hits).
Each hit reduces movement speed by 10% for 12 seconds.

This effect stacks.
After 5 stacks it explodes and does shadow damage.
The explosion also removes Bonecage Armor from players within 5 yards.

Tactic: Shattering Scream

Normal mode
Interrupt this.

On Heoric mode
When the Templars/Bonewardens has 50% hp and Bonecage armor, Players on the Spirit Realm need to stand on the Templars when they have 5 stacks of the Shattering Scream debuff they get from the priestess add in spirit realm.

Spirit Chains

Puts a debuff on a player that does high damage and reduce movement speed by 50% for 30 seconds.
This debuff will unable players to shift realm (prevented from using the Spiritual Fonts).

Tactic: Spirit Chains

Healers
Dispell Spirit Chains all the time.

ADD – SOUL RESIDUE

This add has 2 abilities and can´t be tanked.

Soul Rot

This add leaves dark soul residues behind it when it moves.
If a player stands on it, it does high damage every 2 seconds and reduces damage done by 75%.

Soul Eruption

When this add dies, it explodes and does very high shadow damage to any player within 5 yards and knocking them back.

Tactic: Soul Residue adds

These adds cannot be taunted/tanked.
Have only ranged players in this realm since it will make it much easier to handle these adds.
Range players stand at max range from boss and spread from each other.
Nuke the small Soul residue adds asap and use slow stun abilities on them.

PHASE 2 – The last 30% health

The bosses share health and at 30% (not in LFR), the Desolate Host comes out from the Engine of Souls (the big stone cage) that you fight in living realm. During the last 30%, you will fight the same boss in Spirit Realm and the Desolate Host and Engine of Souls in living realm.

Everything is the same except for the extra abilities from Desolate host.

Tank in living Realm must tank the Desolate host in this phase.

Desolate host has 3 abilities.

Sundering Doom

Boss marks the area around him.
After some seconds it will do millions of damage to all players within 15 yards.
This damage is divided evenly between players in the living realm.

All players in the Spirit Realm will suffer several million in damage that will not be shared between them.
Players further away suffer less damage.

Tactic: Sundering Doom

Players in Living Realm
Stack on Desolate Host boss to share the damage

Players in Spirit Realm
Run far away from Desolate Host to minimize the damage

Doomed Sundering

Boss marks the area around him.
After some seconds it will do millions of damage to all players within 15 yards.
This damage is divided evenly between players in the Spirit realm.

All players in the Living Realm will suffer several million in damage that will not be shared between them.
Players further away suffer less damage.

Tactic: Doomed Sundering