Heigan the Unclean can be either your worst enemy or best friend in Naxxramas, depending on your raids co-ordination this boss can be an impossible hurdle or a simple gear gaining step, though it is easier with this Naxx guide.
The reason this boss has such an unclear divide between difficulty is quite simply because of the four steps you need to dance through to take Heigan down. Failure to complete these steps by a single raid member will most likely result in a wipe, especially in the ten man version of Naxx.
But time to yet again get down to details, Heigan the Unclean has 3,060,000 hit points and as with the 25 man version the 10 man version of Heigan has some crippling disease effects. these affects are spread over two phases, the difference being that phase two also has a much faster motion of the movement pattern that you need to follow.
- Spell Disruption - A 20 Yard AoE focused around Heigan which increases cast times by 300%
- Decrepit Fever - This disease affects a random player and does 3k nature damage every 3 seconds and reduces the maximum hit points of all players within 20 yards by 50%
Heigan will begin to channel the following two spells at the start of phase two.
- Plague Cloud - Deals 7.5k nature damage a second to any player that stays on the platform during phase 2, this can easily be avoided by getting off the platform before phase 2 starts.
- Eruption - During Phase Two three quarters of the room will be hit by eruption every few seconds during phase two. This does 6600 to 7400 nature damage each time. Players near the edge of the safe spot will only be hit once, those in the unsafe spots will be hit multiple times, something that will nearly always kill the affected players!
To defeat Heigan the unclean in 10 man Naxx you simply have to follow the 'dance' which goes from one to four and then back again, as shown in he diagram above. During Phase One you can stand safely on this. In most raid groups the ranged dps and healers stand here in phase one while the boss is tanked through the safe spots at maximum range from the ranged DPS.
Remember it goes from one to four and back again, 1 - 2 - 3 - 4 - 3 - 2 - 1 and so on, remember that this resets at each phase. If your raid group is having trouble with this smoke flares may help!
Apart from that the healers should concentrate on keeping diseases clear and then you should have no problems on this Naxx Boss Heigan the Unclean!