Tanks: Taunt at debuff, run away with debuff.
All others: Flee when boss turns to you. Move away with RoT debuff.
Phase 2: Just stand on a side of the boss with no green stuff. Large insects hurt.
Tanks: Keep boss near outside walls. Taunt when other Tank just gained a stack of anything. Heroic only: Move boss after roars.
All others: Stack close behind boss, including ranged. When affected by Focused Gaze, run to center of room (marked by beacon). Divide raid into two halves that soak Focused Gaze by standing between Boss and target player in alternating turns.
Tanks: Tank Dominator Tentacles, Nightmare Horrors. Keep them away from raid.
All others: Kite blobs to eye, kill them when close to eye. Red patches and swirls hurt. Corruptor Tentacles are #1 target. Always kill all adds before entering phase 2.
Phase 2: Heroism, burst. Players with cricles spread to outer walls. Others move to the heart. Be outside before Heart cast is done.
Spider Phase: Connected players stand together. Move to outside walls with Necrotic Venom debuff.
Transition: Heal CDs against Gathering Clouds. Run/Fly to next platform, group all added spiders in a corner, THEN jump on them to kill them.
Bird Phase: Tanks taunt after Raking Talons. Move to outside walls with Twisting Shadows. Don't stand in frount during Razor Wing. Heroic only: Keep Poison and Whirlwinds apart.
Dragons of Nightmare
Tanks: Tank dragons far away from each other. Around 7 stacks, swap dragons.
Everyone: Divide group into two halves. They stay on their side the entire fight.
All dragons use basic "don't stand in the thing, Interrupt, kill the add" mechanics with no need for explanation. Exceptions: Ysondre: Don't stack. 1 player stands in her flowers.
Lethron, Heroic only: Dispel Shadow Burst, but Defiled Vines has higher priority. Bring more healers if needed.
Tanks: Keep Cenarius near room borders, close to a green path. Add-Tank in center of room. Dip into green to reset debuff. In Phase 2, use major CDs for Spear of Nightmares. Taunt after each, keep boss close to Nightmare zones.
Everyone else: Dip into green zone to reset debuff at 20 stacks. At 15 if Wisps are friendly currently. Dryads heal, interrupt them. Drakes use Nythendra breath and escalate before death; Heal/DPS CDs here. Trees AoE stomp; Stack on Tress. Wisps explode on contact.
Whichever enemy type group stands closest to when they appear will become friendly and spawn a green patch. Remove the most hassling type this way. Wisps are recommended, but YMMV. Trees if no Wisps are coming.
Phase 2: Heroism here. Destroy Roots on Malfurion.
At 95% and 60%. Half of raid starts dreaming. Works like an extra life. If someone HAS to absorb corruption, let these players do it.
Tanks: Taunt at 3. Run out with your debuff, say "dispell [your name]", return.
In phase 2 and phase 3, running our not necessary. Try to let dreaming Tank be active during Nightmare Infusion.
Healers: Only dreaming healers remove tank debuff when tanks tell you to. Do not reach 100 corruption through dispels.
Phase 1: Players with red arrows move out of raid, like Archimonde laser. Dreamers touch small adds. Kill big adds so they are gone when Boss at 65% for phase 2.
Phase 2: Move boss to center, stack on boss. Kill adds, stun/knock back if they reach him. Dreamers soak up puddles.
Phase 3: Move boss to tentacle clumps for cleave, focus and stack on boss. Move out with Nightmare Blades as in Phase 1. When fight will last <30 seconds (~5%), feel free to reach 100 corruption to burst Boss.
Credits: Video guide by FatbossTV
Credits: Video guide by FatbossTV