Guide to LotRO's Ost Dunhoth: Disease Wing

alt="Ost Dunhoth: Disease Wing"
src="http://www.tentonhammer.com/image/view/98264" />

When you first get into Ost Dunhoth, you have a choice of
going left or right. To the left is the href="http://www.tentonhammer.com/lotro/guides/ost-dunhoth/wound">Wound
Wing, which opens up the way to the href="http://www.tentonhammer.com/lotro/guides/ost-dunhoth/fear">Fear
Wing when completed. If you hang a right and then another
right, you reach the Disease Wing (which opens up the way to the Poison
Wing when completed... but more on that later). Strangely, there seems
to be much less disease here than one encounters in the Lost Temple in
the Trollshaws, and there are practically no wights at all.
Nevertheless, Gortheron has set up a nasty, challenging fight in the
corrupted gardens.

The fights here are challenging and interesting. For the
groups of mobs before the boss fight, the damage type is largely acid,
but there are some nasty diseases to watch out for also.

BUGS AND KERGRIM

To get to the boss fight, you must first pass through an
infestation of very nasty vermin - tank-armored gredbyg, enraged
kergrim, gravid grodbog queens and giant-sized glow-worms. There are 3
groups of various sizes and compositions, but there are some
fundamentals that hold true for all three groups:

Some of the mobs here (specifically, the kergrim) feature a
new mechanic that makes CC more challenging: the anger buff. When first
encountered, this buff appears as a shield of red glowing shapes
orbiting around the creature. This buff can be dispelled with CC
attacks - roots and mezzes - but negates the first CC attempt. In order
to keep angered mobs locked down, you need to do a CC "double-tap": hit
with one CC skill, then another immediately after.

With the kergrim specifically, the best strategy seems to be a
Lore-master hitting with Herb-lore first to break the anger buff, then
with Blinding Flash for the mezz. Technically speaking, this process
could be reversed (Blinding Flash, then Herb-lore), but a rooted
kergrim can still attack, and since they have brutal
frontal-area-effect attacks, you want to prevent them from doing so.

Group number one contains 3 Grodbog Deep-Workers (54,348
morale each on Tier II difficulty), and 2 Moria Bone-gnawers (AKA
kergrim; 108,696 morale each). The gredbyg are immune to CC and have a
massive armor buff, but they are slow-moving - at least, until they
start getting attacked. The longer they are in combat geting beat up,
the weaker their shell gets and the faster they can move. The kergrim
have the anger buff, are fast and hit very hard with
frontal-area-effect attacks. 

The strategy here is to have one tank kite the beetles and
have a Lore-master (or, better yet, two Lore-masters) lock down the
kergrim with "double-tap" CC, burning one beetle at a time and then the
kergrim last. Alternately, if there is only one Lore-master (or
otherwise limited CC) in the raid, kill the kergrim first and have the
tank keep kiting the beetles until the kergrim are both dead. Either
way, the raid will want to be fairly spread out for this fight and
squishies will want to keep their distance from the kergrims' frontal
attacks. Keeping the mobs spread out also prevents overzealous
Champions from accidentally breaking CC with area-effect attacks.

Group two consists of 1 Grodbog Deep-worker, 2 Deep-worm
Scavengers (21,966 morale), and 2 Grodbog Queens. The worms have a
range acid-spit attack and are generally a nuisance, but less of a
threat than the queens or the cement-truck beetles. The queens summon
swarms of adds (Grodbog Spawn, 6,624 morale) in small groups. If the
spawn adds are allowed to build up, they can reach ridiculous and
lethal numbers, and when they gang up on a member of the raid, they hit
incredibly hard, tearing through softer targets in seconds. These spawn
occur when players neglect to remove the "bomb" disease in time -
similar to the wipe-causing group-stun wound that occurs in the Wound
Wing - so be sure to pot any disease off as soon as you see it.

The strategy for this fight is for a tank to kite the beetle
while DPS focuses on one queen at a time, killing the worms and spawn
between the two queens. Lore-masters can keep themselves busy here
watching out for diseases on their fellows and removing them quickly to
keep the spawn population under control.

Group three consists of 2 kergrim, 2 queens and 2 worms. For
this fight, use the "double-tap" CC method on the kergrim and kill one
of the queens first. When the first queen is down, mop up the spawn and
the worms and kill the other queen, then the kergrim last. Tanks will
want to focus on keeping the swarm beetles away from the healers. On a
first run-through, this fight will probably be the most challenging of
the three, particularly if copious numbers of gredbyg spawn are allowed
to enter the fray and rip up the healers.

THE GARDEN

Once you're through the ruins and have shaken the pesticide
out of your armour, you encounter the garden of Ost Dunhoth, where
Gortheron is waiting to mock you and introduce you to the next
challenge: Dourbark and Baleleaf, corrupted huorns with entwined roots
and a shared bad attitude. Like any good boss fight with 2 bosses at
one time, the goal here is to kill them both within seconds of one
another. But there are 2 other important parts to this particular
challenge.

Firstly, there's the matter of the sap. As soon as you attack
one of the trees, you are coated with that tree's sap, and the edges of
your screen will turn the appropriate colour (red for Dourbark, white
for Baleleaf). If you switch to
the other tree while coated with the sap of your first tree, you change
saps and fail the challenge for the group. And while you are coated
with one tree's sap, attacking the lurkers it summons forth to protect
it is hazardous - hitting a bog-lurker with the same sap color will
ding you for 25% of your maximum morale. 4 such hits and you die. You
must only attack the lurkers belonging to the other tree, so if you
have red sap, hit only the white bog-lurkers, and vice-versa.

Secondly, the adds come in timed waves. Once the trees
activate, you have only 1 - 2 minutes to do as much damage as possible,
at
which point it throws up a shield and summons forth the bog-lurkers.
Once the lurkers are all dead, the tree becomes attackable again for a
limited time. To beat the challenge, you must face no more than 3 waves.

The raid will need to be split into 2 roughly even teams -
this shouldn't be a problem because that's how the thing works anyway,
2 teams of 6. In this case, however, the DPS for each group needs to be
pretty much dead even. If one side is doing significantly more damage
than the other, it may be impossible to meet the requirement of killing
both trees within seconds of one another without changing sap colors.

Fire damage does well here, so Hunters and Wardens will want
to use Fire Oil for their ranged attacks, and DPS-spec Rune-keepers may
want to spec for fire rather than lightning. If both groups have
Captains, the Captains will want to trait for Oathbreakers, and
Burglars may want to equip the trait that increases the incoming damage
modifier for Reveal Weakness to 12%. Damaging the trees during those
phases will be something like a controlled frenzy - you want to do as
much damage as possible to your tree, but not so much that the other
team can't keep up with it. During each stage, you want to be able to
take 25 - 30% of the trees' morale - roughly 60,000 for each attackable
stage, with the remainder to be burned down after the 3rd wave of adds.

There are a few different ways to handle the adds when they
come in. Ideally, you want a tough tank to wrangle the adds from the
opposite tree over to your side of the room - bring the white-coloured
lurkers to the red tree, and the red-coloured lurkers to the white tree
- but this is easier said
than done. A Guardian's Challenge may inadvertently hit wrong-color bog
lurkers and the Guardian will be unable to drop them for a few seconds.
One method of dealing with this is to have the Guardians charge to the
opposite tree as soon as the text billboards come up announcing the
summoning, and move all melee attackers away from the trees to give the
Guardians some manouevering room. Some groups may prefer to leave their
tank parked at the other tree the whole time, but since that person
can't contribute to DPS on the tree while he is standing on the other
side of the room, this is only really advisable for very high-DPS
groups.

The bog-lurkers come 3 at a time for each side, are
colour-coded to match the trees they protect, and they hit
pretty hard. If you fall and are revived during one of these stages,
you will need to immediately attack your group's tree before hitting
the bog-lurkers to get coated with the proper sap. If you attack a
bog-lurker with no sap, it's the same thing as attacking with the wrong
sap - everyone fails the challenge.

The waves of adds get progressively more difficult each time,
and their behaviour changes after the first wave. For the first wave,
you can simply burn the bog-lurkers one at a time until they are all
dead. For the 2nd and each cosecutive wave, you will want to switch
things up: burn each one down low - 3 - 5000 morale or so - and then
switch targets, burning all of them down evenly and then dispatching
them all more or less simultaneously. This part of the fight is not a
race - Hunters can switch to Precision or Endurance to conserve power
and reduce the likelihood of grabbing aggro from the tank. If one of
the lurkers is killed prematurely, it will spawn another one to replace
it, and keep respawning them indefinitely until all of them die at more
or less the same time (within a few seconds of one another), which
switches the trees back to attackable mode.

Additionally, both groups will want to take down their adds at
the same time. This requires coordination and good communication. When
Group A kills all their adds, Group B's tree becomes vulnerable to
attack. If Group B is still fighting adds, Group A is unable to damage
their tree until Group B's adds are dead, and Group B is missing out on
critical seconds during which they can be doing damage to their tree.
Both groups want to be focused on the same tasks at the same time,
either attacking the trees or killing the adds.

To achieve this, each group will pick a main DPS target
assistant, and the group will target their attacks through that person.
The main DPS target assistant will focus single-target fire on each
add, one at a time, burning them all down to around 3-5000 morale
(enough that lingering damage-over-time effects and stray, accidental
area-effect attacks won't outright kill them), then switch to a fresh
target. After the initial softening, give them a second scrubbing and
bring them down to 2000 morale or less, just enough that a few
area-effect attacks will kill them all quickly, stop DPS and make sure
both groups are caught up to one another. When all six bog-lurkers are
at or around the 2000-morale mark, wipe them out with area-effect
attacks and get back on the trees.

If the raid has two Captains, it may be wise to hold back on
finishing off the lurkers until Oathbreakers is cooled down before
renewing the assault on the trees. If the group has high DPS, this may
not be necessary.

The third wave is likely to be the most difficult; healers
will have burned through most of their big tricks during the 2nd wave,
and a lot of skills will be on cooldown. And if the trees are not
killed after the 3rd wave, the 4th wave will likely be too strong to
handle because everyone will be out of gas. This is one of those cases
where doing the challenge (at least this part of it) is actually easier
than not doing it.

After taking down the infected trees, the way to the Poison
Wing opens up. But before you head there, be sure to loot the big chest
for the armour coin and a chance at a Symbol of the Elder King. These
are the kinds of things you're going to be needing before long - Ivar
is not far off, and then there's the final showdown with Gortheron yet
to come...