Dâr Narbugud/Guide: The Mistress of Pestilence
Preparation
Since there's no intervening trash mobs between The Blind One and The Mistress of Pestilence, the raid can swim west directly from the pool below The Blind One's room and head down the passage to get to the next boss room. The inconsistent mushroom for the deed Dâr Narbugud Fungus Investigation can be found in this passage.
Two tanks are preferred for this fight although it is possible to complete it with one. There is a lot of raid-wide damage during this fight so three healers may be required. Multiple characters capable of CCs (stuns, roots, knockdowns, slows, etc.) are needed to successfully defeat the spores in phase one.
Like The Blind One, The Mistress also has the following buff which makes her immune to Common damage:
Therefore, Guardians and Wardens should apply Shield-spikes to change their shield attack damage type.
Everyone in the raid should have Hope Tokens to counteract the bosses' Gloom effect which applies +5 Dread.
Note: This fight cannot be reset without everyone in the raid being defeated.
Boss fight: Phase 1 (World-eater Protectors)
Prior to engaging The Mistress, the four World-eater Protectors around the room must first be defeated. They must be kept apart because they will heal each other if they get in close proximity to one another. The main tank should pickup aggro on three of the World-eaters and tank or kite them off to the side (the tank will require a lot of healing if they are not kiting). Meanwhile, the offtank should aggro one World-eater and bring them to the raid who should be grouped up near the entrance. The raid should burn them down quickly since just like other World-eaters in the instance they will apply Mark: World-eater's Punishment to their top threat targets when their Morale gets low which will do massive Shadow damage if they are not defeated before it expires.
After the first World-eater is defeated, the offtank should pull a single World-eater off the main tank to the group to be burned down. Repeat for the others one at a time until all four are defeated.
The raid will then be out of combat for a short time while The Mistress speaks dialogue, so that is a good time to eat food and buff up.
Boss fight: Phase 2
From start until The Mistress reaches 50% / 8.3M Morale
At the beginning of this phase The Mistress will become attackable. DPS should immediately start burning her down since she will activate the following effect on the raid:
Aura: Gas Chamber (Acid DOT tiering up every 60s to max tier 4)
The Mistress will also spawn a Protective Fungal Spore and a Reflective Fungal Spore every 10s during this phase. These spores apply the following effects to The Mistress while active:
Protective Swarm (incoming damage buff)
Reflective Swarm (Acid damage reflect)
DPS should be very careful when damaging The Mistress while the Reflective Swarm buff is up since they will reflect 20% of their damage back on themselves. These spores are immune to normal damage and can only be defeated by CC (stun, root, daze, or fear). Certain raid members should be designated to focus on CCing the spores while others focus DPS on The Mistress.
During this phase The Mistress will also periodically do Terrifying Scream which is a massive AOE Shadow damage attack.
She will also periodically apply the following to her target:
Inky Spore followed by 
Killing Field (small ground-targeted Acid DOT that lasts for 60s)
Virulent Contagion followed by 
Distraught (6s root followed by Shadow DOT; removable Fear)
Finally the Mistress will also summon Ravenous Newborns periodically who apply the Daunting Disease debuff to their target.
Boss fight: Phase 3 (Globsnaga Grunts)
In this phase The Mistress becomes unattackable and all of the lights in the room will go out. At this point, three waves of 8-12 Globsnaga Grunts will swarm the raid (one wave every 15s).
The Globsnaga Grunts do frontal AOE damage, so if the raid is grouped up and they are able to get close they could deliver massive damage to the raid. However, they can be CC'd so a good strategy here is to have the raid group up and then as soon as a wave gets in melee range, immediately stun them with multiple CCs and burn them down with AOE. If the raid is lacking in AOE damage then it's best to spread out and deal with each Globsnaga Grunt separately.
Boss fight: Phase 4
From 50% to finish
After the three waves of Grunts are defeated, The Mistress will again become attackable and the main tank should again pick up her aggro while the raid groups up in tight formation. The raid should stay close to The Mistress throughout this phase since acid clouds will appear around the edge of the room that apply the following effect to any therein:
Everyone in the raid will also receive the following effect throughout this phase:
Dampened Morale (reduces Max Morale by 10%)
Soon after the start of the phase and every 60s thereafter, three Snarling Overseer Hatchlings will appear. They will target and move to three raid members at random and stun them with an ability called Channeled Mez. This will stun the characters and apply the following affect after 10s:
Impending End (automatically defeats the character after 20s)
All three of the Snarling Overseer Hatchlings must be defeated quickly before they complete their Channeled Mez to prevent the characters they have stunned from being defeated. Since the main tank can be affected by the Channeled Mez, the offtank should be ready to pickup The Mistress if needed.
Once the Snarling Overseer Hatchlings are defeated the raid can DPS The Mistress until the next wave spawns. Offensive cooldowns should be used whenever they are up to minimize the number of Snarling Overseer Hatchling waves that spawn.
The Mistress will continue to summon Ravenous Newborns who apply the Daunting Disease debuff throughout this phase.
Drops
Loot that drops for all characters
Loot that always drops
Greater Elf-stone of Strength (tradeable for DN armour set chest)
Loot that has a chance to drop
