
Loatheb is a very fun fight; people get to have huge crit buffs and hammer away at a boss for huge numbers!
25 Man
Loatheb is a very flexible fight. A good setup would be 1 tank, 4-5 healers and the rest DPS. There is no advantage in bringing ranged or melee over the other.
10 Man
Loatheb is a very flexible fight. A good setup would be 1 tank, 2-3 healers and the rest DPS. There is no advantage in bringing ranged or melee over the other.
Main Tank: Equip as much HP and avoidance as possible.
Rest of the raid: Equip to maximise your damage or spellpower.
All standard raid buffs buffs, potions and consumables are not required, but make the fight more fun as you can hit for bigger numbers!
25 Man – 18 400 000 HP
Melee hit – Very little. Around 3000 Max.
10 Man – 6 700 000 HP
Melee hit – Very little. Around 2000 Max.
Necrotic Aura – Cast every 20 seconds, this applies a 17 second debuff to everyone in the raid which reduces all healing done by 100% (including potions, healthstones, and bandages). This means that in every 20 seconds, you only have 3 seconds to heal. This debuff affects any heals that land after it is active. For example if you have 1 second left to heal, and cast a large 2 second healing spell, then when the heal lands, the target will have Necrotic Aura already and thus the heal will land for 0. Heal over Time (HoT) spells are also effected by this: the ticks will heal for zero when this debuff is active.
Deathbloom – Cast every 30 seconds on everyone in the raid, this debuff does 400 damage per second (200 damage per second in 10 man) for six seconds and then does a burst of damage for 1500 when it expires (1200 in 10 man). It is undispellable.
Inevitable Doom – This is first cast after 2 minutes in combat. It is a 10 second cast that inflicts 4000 damage on everyone in the raid. It is cast every 30 seconds thereafter for 3 minutes. After these 3 minutes, it is increased to every 15 seconds. It cannot be avoided except by immunity effects (Divine Shield, Iceblock etc.).
Fungal Spore – A Fungal Spore is summoned from one of 4 locations around the room every 30 seconds. These are beneficial to the raid and when spawned will float slowly towards the raid. They cannot be tanked or have their movement controlled. They have 7500 HP (3000HP in 10 man) and melee hit for 20-30 damage. You can only have 2 Fungal Spores up at a time (older ones will despawn), but usually you will kill them shortly after they spawn anyway.
Fungal Creep – When destroyed, a Fungal Spore applies a non stacking buff called Fungal Creep to 5 players within 10 yards of the Fungal Spore, increasing their critical strike chance by 50% and making all abilities cause no threat. This buff lasts 90 seconds. Tanks should avoid this because, if they gain the buff, they will no longer build threat on the boss. While the buff is great for adding DPS it is not required to kill the boss, however it is recommended to gain it. If you avoid killing the Fungal Spores at all for the entire fight you will also gain an achievement. The Fungal Creep buff does stack with your current crit rate and raid buffs; so if you had a 40% crit rate before the buff, you would have 90% after.

Have your main tank run in and pick Loatheb up. Hunters should Misdirect Loatheb onto the main tank to maximise his or her threat. The rest of the raid should follow the main tank and get into position. It is recommended that the majority of the raid stays in one group away from the main tank to help him avoid the Fungal Creep buff.

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Once the main tank has pulled Loatheb into position and DPS has started you will have very little time before the first round of debuffs (Necrotic Aura, Deathbloom and Inevitable doom) are applied. Use this time wisely to heal the main tank to full HP from any hits he may have taken. Once the first Necrotic Aura, and then Deathbloom 10 seconds later, are applied, the clock is effectively “ticking” to DPS the boss down before your healers run out of mana or, more likely, the increasing amount of damage caused by Deathbloom and Inevitable Doom starts killing people. However, it should be noted that this is not really an enrage because, as people start dying, the actual healing of the raid becomes easier; thus evening out the losses incurred and making it possible to last for longer. Of course, if the main tank or a healer dies, this principle will not hold true.
Healers need to wait until the Necrotic Aura fades then heal the raid up in the 3 seconds they have. Generally 2 people will use large heals on the main tank to top him off while the other healers use AoE heals on the raid. Once the tank has been topped off, the healers on him will assist healing the raid up if possible. If, as a healer, you believe mana is not an issue for you (eg. you are always at high levels of mana and would otherwise be stood there doing nothing), you can assist DPSing the boss during the healing blocks as long as you still retain enough mana to heal when the block next fades.
Tips for healers dealing with Necrotic Aura: Healers should be aware that Necrotic Aura only affects any heals that land whilst the debuff is up. This means that, should you start casting a 3 second heal 2 seconds before the Necrotic Aura fades, when it lands 1 second after the Necrotic Aura fades it will heal the target successfully. On the other hand, if you start a 3 second heal 2 seconds before the Necrotic Aura is renewed, and it lands after the Necrotic Aura has been renewed, it will not heal the target. This is also true for HoT ticks.
For DPS, once you have started you will need to wait for the first Fungal Spore before doing anything important (you should still be attacking the boss, but that is all you need to think about). Once the Fungal Spore has spawned, wait for it to float towards the raid slightly (to avoid DPS downtime on the boss) before grouping up around it and killing it to gain the Fungal Creep buff. It is important that the Fungal Spore is killed away from the tank so that he can keep building threat. This can either be ensured by having 5 people closer to the Fungal Spore than the main tank when the Fungal Spore is killed; or by the main tank moving away from the Fungal Spore (because Loatheb hits weakly and has no special abilities to consider, moving him is simple). It will take several Fungal Spores before everyone gains the buff and healers are also recommended to gain the buff when and if they can.
Continue repeating the above procedure until the boss is dead.
Top Tip Regarding Fungal Creep: With this buff lasting for 90 seconds and a new Fungal Spore appearing every 30 seconds, in a 25 man raid 15 people can gain the buff at any one time. In order to maximise raid DPS it is recommended that people keep a close watch on the time left on the Fungal Creep and do not renew it until it has actually worn off. You might arrange a rotation where group 1 would kill Fungal Spore one, group 2 Fungal Spore two, group 3 Fungal Spore three and then group 1 would kill the fourth Fungal Spore and so on (depending on your raid setup). Alternatively, you can simply have DPS players without the buff run to the Fungal Spore each time, but be careful that at least 5 players go each time to avoid Fungal Creep landing on the tank.
Main Tank: Use your abilities to avoid taking as much damage as possible.
Healers: Maximise your output in the 3 seconds you have between Necrotic Auras. Focus on topping off the main tank quickly and then using area of effect heals, especially on the lowest HP raid members.
All DPS: DPS Loatheb until the Fungal Spores spawn. When a Fungal Spore spawns, hug it and then kill it for the Fungal Creep +50% crit buff. Once you have this buff, continue to kill Loatheb.