As usually, these tactics are my own and does not mean they are the most optimal.
The Emerald Dream was entrusted to Ysera for safekeeping, and the mightiest of her green dragon brood were assigned to stand watch over four portals that connected directly to Azeroth. But even before the Cataclysm, these dragons began to show signs of corruption. Now, the path to the Nightmare's core runs through the dragons' lair.
There is one main dragon (Ysondre) and 3 other dragons (Emeriss, Lethon and Taerar). To make this easier, the three other dragons are now called Nightmares.
1 of the 3 Nightmares will not take part in the fight each week and its random of whom it is. Meaning, you will fight Ysondre and 2 other Nightmares (Emeriss, Lethon or/and Taerar) and the third nightmare will not take part in the fight.
Ysondre share health with the Nightmares.
The encounter starts with Ysondre and one of the Nightmares.
When Ysondre is at 70% health, the Nightmare on the ground will fly up to the air and a new one will spawn from a portal and fly down. Ysondre will never fly up, only her nightmares.
When Ysondre is at 40% health, the two Nightmares will swap again.
When a Nightmare is up in the air it differs between Normal/Heroic/Mythic difficulties. On LFR/Normal mode, the Nightmare in the air doesn’t do anything. On heroic/mythic, the Nightmare in the air has an “air” ability.
Ysondre and her Nightmares have 2 shared abilities:
Breathes Corruption in a frontal cone.
Mark of the Nightmare
Each dragon on the ground puts a debuff on close players, after 10 stacks the players is stunned for 30 sec.
They also have 2 of their own abilities (3 with air phase on heroic/mythic).
A Nightmare ball on a player location, creating a Flower that spawns add.
Call defiled spirit
A large circle on the ground, rooting players in it and explodes after a short time.
Essence of Corruption
Adds that spawn around dragon
Infection debuff that does damage every 3 sec and spreads to other players within 10y.
Souls fragments spawns from each player moving towards Lethon and heals when they reach.
Nightmares that fall from the sky.
Shade of Taerar
2 extra dragon images spawns doing breath as well.
Green Fog spawns randomly moving slowly and puts players to sleep if it touches them.
Have each dragon on each side of the platform, one tank on each side.
Divide the raid in two groups with more or less equal amount of ranged dps, healers and melee dps.
Everyone spread from each other.
Face the dragons away from raid.
Mythic difficulty: Melee stand next to the boss, not behind because they hit hard with their tail.
Mark of the Nightmare
Each dragon will periodically mark all players within 45 yards with a debuff that does low shadow damage every second.
When reaching 10 stacks, the player is stunned for 30 sec.
Tactic: Mark of the Nightmare
The tanks will swap dragons.
After 7 stacks, meet up in the middle and taunt off each other’s dragons, then run back to same position again and face the dragon away from raid.
Stay where you are, do not run to the other side.
The debuff goes away after 35 seconds so when the dragon comes back later, that debuff is gone.
The dragon breathes out corruption in a frontal cone.
Tactic: Corrupted Breath
Do not stand in front of the boss
Make sure the dragon is faced away from raid
Use defensive ability.
Ysondre personal abilities
Launches a ball of nightmare essence on a players location.
Does shadow damage and knockback.
The impact creates a flower (Nightmare Bloom) which does damage every 3 seconds.
If no players stand on the Bloom, it will spawn adds (Dread Horror).
Dread Horror does melee damage
Standing close to a Dread Horror causes a damage reduction on that player by 50%.
Tactic Nightmare Blast
- Move away from the ball impact.
- Easiest will be, that the person that is targeted by the Blast will then stand on the Bloom.
- Healers beware of that player taking damage for a long period of time.
- Beware that one Dread Horror add will always spawn directly when the ball lands.
Call Defiled Spirit
Calls out a druid spirit (a large purple circle) that spawns on a ranged player, which roots and then detonates doing large amount of damage to anyone in that circle.
Tactic: Call Defiled Spirit
Stay spread from each other so no other players will be hit by it.
If you are targeted, move away asap once dispelled.
Use own spells if you have to escape the root (Blink, Blessing of Freedom etc).
Dispell the root fast.
Emeriss personal abilities
An infection debuff doing nature damage every 3 seconds for 1.5 min.
This infection also does damage to other players within 10 yards.
This cannot be dispelled.
Tactic: Volatile infection
Make sure you are spread from each other all the time and this will not affect other players
Essence of Corruption
Adds called Essences of corruption will periodically spawn around Emeriss.
These adds do shadow damage to ALL players (no matter how far away)
Tactic: Essence of Corruption
Pick up the adds and tank them together with Emeriss
Focus these adds only and aoe them down fast.
Heroic/Mythic: Corruption of the Dream
When this Nightmare dragon is in the air she will buff all mobs.
This buff spawns a mushroom when a mob die and explodes, doing Nature damage to players nearby.
Tactic: Make sure to move away from the adds asap when they die.
Lethon personal abilities
Pulls a soul fragment out of players.
This soul fragment will be drawn to Lethon.
Each fragment heals him and Ysondre when it reaches Lethon.
Tactic: Siphon Spirit
The group attacking Lethon
When Lethon casts Siphon Spirit: Move far away from him to a certain position and group up.
Aoe/cleave the fragments that spawned.
Move back to position when they are destroyed.
The group attacking Ysondre
Melee destroy the fragments coming from melee players first then help on others if needed
Ranged destroy the fragments coming from ranged players first, then help out on others if needed.
Lethon causes nightmares to periodically fall from above, doing Shadow damage to players within 10y of the impact area.
Stay spread and dodge the nightmares.
Heroic/Mythic: Shadow Burst
When this Nightmare dragon is in the air he will target a player.
After 10 seconds, shadow magic spreads to the three nearest players doing shadow damage every 3 sec and reduces movement speed by 10% for 21 sec.
This effect stacks.
Taerar personal abilities
Shade of Taerar
Taerar spawns 2 images of himself (with less health and damage).
These images share the same abilities as Taerar himself – Corrupted breath (and tail lash heroic/mythic).
Meaning, when this dragon does corrupted breath, the 2 images will also do that which will do very high damage on the tank.
Tactic: Shade of Taerar
Face the dragon and the 2 images away from raid.
Use defensive cooldown when they do breath.
Focus nuke the images
Use defensive/heal the tank up asap.
The Dragon spawns several fogs that moves slowly around the entire platform. If a player comes into contact with the fog, that player is put to sleep for 6 sec and take ticking nature damage ever sec.
Tactic: Sleeping Fog
Move away from the fog and keep staying spread from each other. Important for the other group that attacks Ysondre as well since it is very important you stay spread there.
Heroic/Mythic: Bellowing Roar
When this Nightmare dragon is in the air he will release a roar that causes all players to run in fear for 3 seconds.
Tactic: Make sure you are spread from each other all the time before and after the roar.
If you have problems with adds spawning from the flower (from Nightmare blast that Ysondre does): For the soaking part, assign a certain class that can remove the fear, for example Mage Ice Block, Paladin Divine Shield etc.
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