Patchwerk. Don’t worry about the mechanics, unless the exploding bugs during the intermissions are causing you problems (in which case, just move a small distance away from them).
Almost every ability will give you a stack of Infested. Nythendra will cast Infested Mind after every Infested Breath: if you have 10 stacks or more of Infested you’ll become mind-controlled and the fight will end, UNLESS you’re a tank. This means that you really need to solo this version of the fight in a tank spec, even though it may be tempting to switch to DPS for a faster victory.
Dragons of Nightmare
Just burn them down. If both Taerar and Rothos are active, Rothos will spawn Seeping Fog clouds: avoid them since they’ll put you to sleep for six seconds. If your DPS is good, you’ll finish the fight before you accumulate ten stacks of any dragon’s Mark debuff and fall asleep for thirty seconds due to Slumbering Nightmare. If not, try to pop any long-duration HoTs or defensive CDs when you hit nine stacks, and you should survive.
This is an INTENSE DPS race/survival fight! Stacks of Overwhelm and Rend Flesh build up quickly, and will kill you just as quickly. Save all of your defensive cooldowns for his Blood Frenzy, and you may survive long enough to kill him.
Every time Ursoc casts his raid-wide Roaring Cacaphony AoE, he spawns a temporary Nightmare Image in his location. Each image creates a nasty Miasma pool that you need to run out of ASAP; additionally, each image will cast Nightmarish Cacaphony when Ursoc casts his Roaring, contributing to the massive ramping damage of the fight. You’ll need some pretty hefty damage mitigation and DPS cooldowns to have a chance.
This is essentially an add fight with two burn phases. Nuke tentacle and horror adds as they appear, paying special attention to Corrupter Tentacles. These mobs will apply Spew Corruption, which causes damage and makes you drop pools of corruption: these pools can make it difficult to move around when they become too numerous. Every add you kill will spawn Nightmare Ichors: bring these to the Eye and kill them there, as it takes twenty of their dying explosions to disable the Eye and open the inner chamber. You will have fifty-five seconds to attack Il’gynoth before Dark Reconstitution ends; if you’re still inside at this point, you will be instantly killed. The add phase will repeat, and you will have ninety seconds to KILL Il’gynoth before you’re killed by Final Torpor.
When Nightmare Ichors die, their Nightmare Explosions place a Nightmare Explosion DoT on you. It’s not huge, but it can take you by surprise if you nuke a large group of ichors at once near the Eye. Illy gains the Death Blossom ability, which is meant to be soaked by the (non-existent) raid: you’ll be taking a LOT of damage from then long-lasting Dispersed Spores DoT from the unsoaked puddles.
Don’t stand in purple or green crap. Cleave adds down in the spider phase. Don’t fall off the world when using the feather to switch platforms. Razor Wing does a large knockback and should be avoided. That’s it.
A fairly simple fight, really. Just kite Cenarius around the room to avoid being rooted by Nightmare Brambles. Your stacks of Creeping Nightmares will get very high, but the fight seems to be bugged as Malfurion rarely (if ever) puts down patches of Cleansed Ground to help you remove your stacks. When Cenarius reaches thirty percent, he will start attacking you with Spear of Nightmares, which does little damage but forces you to drop pools of Nightmare on the ground. This phase is a race to kill Cenarius before your Creeping Nightmare stacks kill you, while dodging pools of Nightmare and the annoying Nightmare Brambles. Enjoy!
The Ally of Nature adds become hostile when Cenarius casts Forces of Nightmare, so there will be a LOT more of them running around. The spawned Nightmare adds have new abilities, but as usual, they just make the fight messier and a bit more annoying. Cenarius himself gains Nightmare Blast in Phase 1, which is the tank swap mechanic (since there’s no other tank to swap with, you get to eat all the damage). In the second phase, Cenarius will summon walls of Beast of Nightmare adds: avoid them if you can, ignore them if you want.
A fairly simple DPS race. At the start of the fight you’ll get put into a dream trance, where you’ll stay and fight until you reach full corruption. At this point you’ll be pulled back to reality and your corruption will reset to zero, and you will receive the Corruption: Descent into Madnessbuff (but won’t become Charmed when it expires). When you’re fully corrupted, you’ll get the buff again, but this time the fight will reset if you don’t kill Xavius before it expires and you get Charmed.