Loatheb is a gigantic plague ridden bog beast from Azeroth who has been beefed up to the max in Wrath of the Lich King. Loatheb is particularly akward for most raid groups due to his quite painful 100% anti-healing spell, which gives your raid no healing ability for 17 out of every 20 seconds of the boss fight.
This Naxx fight has become significantly more difficult since the priests AoE healing spell Circle of Healing was nerfed (Yes, they nerfed possibly the weakest, most expensive healing spell since Holy Nova was removed from the Talent Tree) to a six second cooldown, it has been considered that this fight is the sole reason this happened.
This massive gimp on healing may make the fight seem near impossible, and indeed to an unprepared raid group this fight is impossible, fortunately there plenty of ways you can boost your raid group to get it through the fight. Deadly Boss Mods is pretty much essential during this boss fight since you have so few oportunities to heal the raid members!
So lets get on with the basics on this boss, Loatheb has 6,690,000 hp and has pretty weak attacks, as mentioned earlier the real danger from Loatheb is from his anti-healing spell Necrotic Aura.
Loatheb has several abilities and effects, near unique is the fact that Loatheb gives out a positive buff,
- Necrotic Aura -Every 20 seconds Loatheb will cast Necrotic Aura on your entire raid group. This will reduce all healing by 100% for 17 seconds. This does mean you only get one 3 seconds chance to heal every 20 seconds!
- Deathbloom - Once every 30 seconds Loatheb will cast Deathbloom on the raid, giving a DoT that does 200 nature damage a second for six seconds with a final 1200 natura damage hit at the end. This is unfortunately undispellable.
- Inevitable Doom - Once two minutes has passed Loatheb will begin to cast Inevitable Doom. This inflicts 4000 Shadow Damage after 10 seconds and is cast every 30 seconds. 5 minutes after the fight started this will go down to every 15 seconds. This cannot be dispelled however but Ice Block, Cloak of Shadows and Divine Shield will remove it.
- Fungal Creep - This is a pretty much essential ingredient to this fight. To take down Loatheb you need to nuke him down as fast as possible, this buff gives a 50% critical strike chance and cause no threat for 90 seconds. You receive this buff by killing spores that Loatheb will spawn every 30 seconds. This cannot be held by more than 5 people in the raid so this should only be picked up by your DPS.
Your DPS should be in one group if possible and be followed by a priest with CoH and Precast ready on Prayer of Healing. Before this fight all classes should be awae of their own healing abilities and be able to time them in to the fight (I.E Deathnights get a full set of runes to pull off two Death Strikes, Warlocks cast Haunt 12-13 seconds before Necrotic Aura fades.
Since healers tend to be next to useless for a large portion of the fight it is a great idea to have the healers anouncing new spores, heal points, (10-11 seconds HoT's spammed over raid, 3 seconds for long cast large heal spells to be cast on those on significant low HP)
Position wise the tank and Loatheb should be kept well away from any spores, this is pretty much essential, if the tank gets hit with the spores buff they will instantly lose threat/agro. Later on (after the third spore) it is possible for 100% of your group to get the Buff. This needs careful work but can be hugely benefitial to the raid group, but the next spore must be gained by the DPS to avoid threat being taken away from the tank.