The Nighthold

[joaovsmiranda]

STAR AUGUR ETRAEUS
WoWHead Guide

Spoiler:

As mentioned before, none of these spells are casted by the boss, and their abscence make the boss almost a DPS dummy:
Coronal Ejection
Icy Ejection
Fel Ejection
Void Ejection

Also, the following impacts are not dealing any damage to the primary target (usually the tank):
Comet Impact
Void Impact

The Comet Impact should apply Absolute Zero to it's primary target, which isn't happening.

And the Fel Impact should happen only 3 times for each Gravitational Pull, but it's happening 4 times.

TICHONDRIUS
WoWHead Guide

Spoiler:

The adds on second phase 1 (Felsworn Spellguard) aren't being affected by Vampiric Aura, so they don't get healed when close to the boss. I couldn't check the adds from the 3rd phase 1 because boss died before that.

Also, I can't say for sure, but the melee damage from the adds (Tainted Blood) are way below it should be (80-150k), so even with Vampiric Aura they die very quickly near the boss.
This video shows the adds hitting the tank for 300-350k each hit: https://youtube.com/watch?v=-irsjhCjGJs:


This may be valid for Felsword Spellguards too, as they were hitting for less than 100k.

GRAND MAGISTRIX ELISANDE
WoWHead Guide

Spoiler:

The spell Spanning Singularity is being casted only on some ranged targets, when it should be random. We had a only melee raid, only with a holy priest and myself as a MW monk, and she was casting this spell only on the priest. After he died, she never casted it again at all.

This probably happens with Delphuric Beam too, because she didn't cast it a single time (the priest died in Time Layer 1).

Also, in Time Layers 2 and 3, Spanning Singularity wasn't echoed at all, when it should spawn at the same spot and same time it happened in Time Layer 1 (maybe it didn't happen because priest was dead, but can't be sure without test).

Finally, the Recursive Elemental is spawning always at the same location, when it should be random.

[Flashmoo]

Boss: Gul'Dan (Mythic)
Spells: Liquid Hellfire/Empowered Liquid Hellfire
Bug description: In Phase 1, Gul'Dan should cast Liquid Hellfire at rdps/healer location.
The problem is that in the location where Liquid Hellfire was launched, there should be an Empowered Liquid Hellfire aka green pool on the ground. Right now, the Empowered Liquid Hellfire isn't working and Liquid Hellfire is casted only once (should be three times in succession, 5 seconds apart).

Proof:

Spoiler:

"In addition, on Mythic Difficulty, after Gul'dan reaches 70% and gains Empowered Liquid Hellfire, each Empowered Liquid Hellfire will be dropped three times in succession, 5 seconds apart, instead of just once, creating three liquid hellfire pools. Ranged DPS should bait each of the three pools away from the raid."
https://www.wowhead.com/guldan-nighthold-raid-strategy-guide

Boss: Gul'Dan (Mythic)
Spells: Storm of the Destroyer vs Empowered Eye of Gul'dan
Bug description: In Phase 2, after Gul'Dan is casting Storm of the Destroyer, he should summon an Empowered Eye of Gul'dan and THEN teleport to the tank o the other side of the room.
The problem is that Gul'Dan is not teleporting to the tank, he stay and cast Empowered Eye of Gul'dan.

Proof:

Spoiler:

"One bad crossover point is after the second Storm of the Destroyer is cast. Before teleporting to the tank, he will summon an Empowered Eye of Gul'dan."
https://www.wowhead.com/guldan-nighthold-raid-strategy-guide

Boss: Gul'Dan (Mythic) / The Demon Within
Spells: Sheared Soul vs soaking players
Bug description: In Phase 3, The Demon Within will cast Soulsever mainly on tanks, that will apply Sheared Soul and in order to remove/replace this debuff, a player have to soak the tank image from his back (Sheared Soul).
The problem is that on our server we need to soak the Sheared Soul multiple times in order to replace the Sheared Soul from tanks with Severed Sou.

Proof:

Spoiler:

min 21:08
https://youtube.com/watch?v=dFgTGGWIILo:

Boss: Gul'Dan (Mythic) / The Demon Within
Spells: Visions of the Dark Titan vs Time Stop Field vs Demonic Essence
Bug description: In Phase 3, right before Visions of the Dark Titan, Nightorb need to be killed in order to spawn the Time Stop Field, and Soul Fragment of Azzinoth need to be killed in order to spawn Demonic Essence. Then you have to stay in Demonic Essence pools, heal them until 100% so they will apply Demonbane on boss and enter in Time Stop Field.

The problem is that, all the players from Time Stop Field are NOT immune to everything. Right when the boss is casting Visions of the Dark Titan and all players are in Time Stop Field -> all players will die even if Demonic Essence is healed to 100% OR the boss will reset and Gul'dan will spawn.
Also, Demonic Essence should transform to Purified Essence, but there is not visual effect for it. I personaly believe that Purified Essence doesn't have a delay and is instantly killing people even if they are in the Time Stop Field.

Guldan can be killed ONLY, if you have strong dps and avoid Visions of the Dark Titan.

This is the same problem from the last patch 7.1.5

Proof:

Spoiler:

"For the 1st Visions of the Dark Titan, everyone stand inside the Demonic Essence next to Nightorb 1 and heal it up to full. While it is being healed, kill Nightorb 1 and then run into the Time Stop Field."
https://www.wowhead.com/guldan-nighthold-raid-strategy-guide

Retribution Paladin Guide PvE | In-Depth 7.3.5
Protection Paladin Guide PvE | In-Depth 7.3.5
Holy Paladin Guide PvE | In-Depth 7.3.5

[Midius]

Boss: Elisande (heroic, mythic)
Spells: Time stop and Delphuric beam
Bug description: At the transition between phases 2 and 3, if Elisande doesn't complete the cast of Delphuric beam before she reaches 10% when she is untargetable her cast will still buff her (you can't see this but you can deduce) and then two things can happen:
(a) either she will still stun all players with Time stop before she transitions into phase 3, in which case she will keep firing the spell at players from the nightwell, and if a player doesn't use some form of defensive before the stun and is targeted two times there is no way to deal with this;
(b) or she won't stun anyone and you can actually heal through the transition, and again she continues targeting players with delphuric beam from the center.
Both behaviors are incorrect, because the time stop should remove this, but it's bugged and is very annoying on mythic difficulty (personally I have seen both behaviors on heroic too).

I have proof only for the second case (the first is more problematic), but I think someone else can confirm the first one since it happens very frequently.

Proof:

Spoiler:

Example of what happens on freakz, on mythic