Ost Dunhoth Disease Wing — Corrupted Huorns

This guide covers the Disease Wing of Ost Dunhoth, from the trash leading up to the Corrupted Huorns boss fight through the T2 Challenge strategy.

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Desired Stat Percentages

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Instance Loot Reference

T2 Challenge

Kill both corrupted Huorns — Baleleaf and Dourbark — within 10 seconds of each other, while only killing two waves of Bog Lurkers (12 total).

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Trash Pulls (Lead-up to Boss)

There are three small pulls of adds before you reach the corrupted trees, consisting of Kergrim Bone Gnawers, Grodbog Workers, Grodbog Queens, and Deep-worm Scavengers.

Mob Breakdown

Kergrim Bone Gnawers

• Have the Anger buff, rendering them immune to the first crowd control (CC) thrown at them. You must break this buff with one CC skill before a second CC will stick.
• Recommended to use a daze to lock these down after breaking Anger.
• After 50 seconds the Anger buff will reapply — watch timers and be ready to re-CC.
• Have a nasty distributed hit — all melee must stack tightly together to split the damage evenly.

Grodbog Workers

• Have the Thickened Shell buff. As they take damage, their run speed increases, making them progressively harder to kite.
• Must be kept moving so they cannot induct their larger hits.
• Deal morale damage to their target equal to 35% of the target's max morale every 25–30 seconds when in melee range. Extremely dangerous when multiple Workers use this at the same time.

Grodbog Queens

• Apply diseases to players that must be cleansed before they expire. If a disease expires, it spawns small beetles that deal rapid damage to their target.
• More damaging attacks are ranged, so tank them in melee range.
• Reduce their target's Resistance rating considerably.

Deep-worm Scavengers

• Summon disease fields that deal damage over time — don't stand in them.
• Each Lord will have two thralls.
• Die relatively quickly and are the lowest-priority mobs in these pulls.

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Pull 1

1. Ranged and healers stay at the top of the stairs to avoid the Kergrim's distributed damage.
2. Initiate with CC to break the Anger buff on the Kergrim.
3. A Burglar riddles the farther Kergrim while the tank pulls one away so the group can begin DPS.
4. A Lore-master applies Sticky Tar at the base of the stairs to slow the Grodbog Workers.
5. The kiting tank taunts the Workers and pulls them back into the entrance cave, kiting them until both Kergrim are dead.
6. Watch the Anger buff on the locked-down Bone Gnawer — re-CC before it expires.
7. Once both Kergrim are dead, the kiting tank runs back to the stairwell and the DPS group single-targets the Workers. Avoid excessive AoE — if all Workers get speed-buffed they will catch the tank and land unavoidable morale damage.

Pull 2

1. The kiting tank pulls one Worker back to the main hall while the main tank grabs the remaining mobs.
2. Tank the Queen in melee range — her more damaging attacks are ranged.
3. Cleanse all "Impregnated" diseases immediately or you will spawn multiple beetles with extremely fast attacks.

Pull 3

1. Break both Bone Gnawers' Anger buff and keep one or both locked down while you kill the Queens.
2. Remove diseases and step out of disease fields left by the Deep-worms.
3. Tank the Kergrim on the stairs away from the ranged group — make sure melee are stacked for distributed hits.

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Boss Fight: Corrupted Huorns (Baleleaf & Dourbark)

The challenge is a DPS race with no hard enrage timer. Split the raid into two balanced groups with roughly even DPS potential.

Raid Setup

• Two groups, one per Huorn (Baleleaf and Dourbark)
• Each group needs: 1 tank, 1 healer, DPS
• In each group, designate one DPS as the Bog Lurker coordinator — this person calls when to stop and start DPS on Lurkers. Pick someone comfortable leading and making quick calls.

Huorn Mechanics

• Huorns periodically use an AoE frontal stun on the tank. Tanks must face them away from the group at all times.
• They have strong melee attacks — it is widely considered easier to ranged-tank them if possible.
• Huorns will periodically become unattackable and spawn Bog Lurkers.

Bog Lurker Phase

This is the most dangerous and coordination-heavy part of the fight.

1. Lurkers spawn in groups of 3 around each Huorn.
2. When Lurkers become active, everyone runs to the middle and keeps moving until tanks have aggro.
3. Tanks must swap Lurkers — pick up the opposing side's Lurkers and bring them to your group.
4. DO NOT attack Lurkers before the tank swap is complete. Damaging the wrong-coloured Lurker reflects 25% damage per hit back to the attacker. This will easily kill AoE DPS.
5. Absolutely no bleeds on Bog Lurkers — DoT ticks on wrong-coloured Lurkers during the swap will reflect and kill you.
6. Bring all Lurkers on your side down to roughly 10–20% morale, then stop DPS and wait for the coordinator's call.
7. All Lurkers must die at the same time. If they don't, a new wave spawns from the survivors — and you only get two waves for the challenge.
8. Kill Lurkers near their Huorn so DPS can quickly switch back to the boss when the burn phase starts.

Sticky Sap & Colour Mechanic

• Each Huorn applies a sticky sap disease that colour-codes you to that side.
• Never attack the opposing Huorn while you have their sap colour — this fails the challenge.
• If a group is struggling for DPS and you want to help the other side: intentionally reflect yourself on a Lurker when you have Desperate Not to Fail (DNF) or a revive available. This clears your sap and frees you to attack the other Huorn.

Cooldown Management

There is no hard timer on this fight. When Lurkers are active, you may keep 2 alive and whittle them down slowly while waiting on major cooldowns before killing them and restarting the Huorn burn phase.

Key Reminders

Rule	Why It Matters
No AoE/bleeds on Lurkers before swap	25% reflected damage per hit — instant death
Follow your Lurker coordinator	Uncoordinated DPS spawns extra waves, failing the challenge
Stack melee on trash Kergrim	Distributed hits will one-shot isolated players
Cleanse diseases immediately	Expired diseases spawn beetles or fail mechanics
Tanks face Huorns away	Frontal stun hits the entire group otherwise
Kill Lurkers near the tree	Faster transition back to boss burn phase
Tanks kite Lurkers if healing is strained	Tanking both Lurkers and the Huorn simultaneously can overwhelm healers

Recommended Consumables

Ost Dunhoth Disease Wing features heavy disease pressure and distributed damage. Come prepared:

Consumable	Example	Purpose
Cooked Food	Superior Supreme Rations	Primary stat food for your class
Trail Food	Supreme Trail Provisions	Trail food — mitigation buffs
Battle Scroll	Scroll of Supreme Battle Lore	Offensive mastery buff
Warding Scroll	Scroll of Supreme Warding Lore	Defensive mitigation (critical for tanks and Lurker swaps)
Hope Token	Supreme Edhelharn Token	Hope — counters the dread in Ost Dunhoth
Athelas Essence	Supreme Athelas Essence	Emergency morale between phases
Celebrant Salve	Supreme Celebrant Salve	Power sustain during extended Lurker phases

Tip: Disease cleanse pots are essential in this wing. The Grodbog Queens and Deep-worm Scavengers apply diseases constantly — have extra pots on your quickbar.

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Guide based on notes by Tinnuviel and strategy by Robrelloth of WwE. Adapted for lotroguides.com.