Netherspite

Netherspite - Part 1

Netherspite is an immense nether dragon found lurking in the Celestial Watch, Medivh's personal observatory. As the only dragon found inside the dark tower, it will use its otherworldly powers to vanquish any creatures that attempt to go near it. This dragon's death is not required for further progress into the tower but he does control the trash between the Shade of Aran and the Chess Event.

Prior to Battle

Netherspite patrols the back section of his room, but his aggro radius is not particularly large, allowing the entire raid to comfortably enter the room before the pull.

Attacks and Abilities

Basic Melee: Netherspite hits for roughly 8k on cloth, without any buffs stacked on him.
Nether Burn: Aura type spell, deals 1200 shadow damage every 5 sec, affected by line of sight. This damage is resistible, so shadow resist buffs beforehand can negate much of it. Only active during Portal phase.
Void Zone: Opens a massive void portal that lasts 25 sec., inflicting ~1k shadow damage every 2 sec. to all enemies in the selected area. (Similar to that in the Four Horsemen fight of Naxxramas, or Zereketh the Unbound in Arcatraz) Simply move out of the affected area immediately.

Netherbreath: An attack hitting everyone in a cone out from where Netherspite is facing at the time for 4500 arcane damage in addition to knocking them back for ~20 yards. Will be cast very frequently during Banish phase. Cast time: 2.5 seconds.
Empowerment: Undispellable self-buff that increases damage by 200%. Cast during Portal phase a few seconds after beams come up and will remain for the whole phase.
Enrage: After 9 minutes, Netherspite will enrage, increasing his damage done by 500% (including Nether Burn). Will generally make quick work of your raid, dealing upwards of 30000 damage per hit in melee.

Strategy
There are two phases to this fight, which alternate between each other. The Portal phase, which is the first one and lasts for a minute, and the Banish phase, which lasts for half a minute. They alternate until the encounter is over or Netherspite enrages.

During all phases Void Zones will spawn under random players, dealing large amounts of shadow damage in a short frame of time to those who aren't moving out of them quick enough.

Portal phase
At the beginning of this phase, three portals of different colors will spawn at fixed locations in the room and will begin emitting a beam of their respective color (see below) towards Netherspite.

If the beams are allowed to hit Netherspite freely, they grant him stacking buffs which strengthen or even heal him. The buffs on Netherspite last 5 seconds from last application (instead of the 8 to 20 seconds it does on players). The beams can (and must) be blocked by players who position themselves between a portal and Netherspite. Players blocking the beams are also affected by a stacking buff, having a positive and a negative effect which grow with each second that they spend inside the beam. Although the positive effects are quite helpful for the fight, the negative effect makes it hard to nearly impossible for one player to block a beam for the complete duration of the Portal Phase.

Once a buff "ticks out" (player leaves the beam long enough to lose the debuff - 8-20 sec), another debuff is applied to the player called Nether Exhaustion, which prevents him from intercepting that color beam for the next 1 minute and 30 seconds.

Red Beam Perseverance (red) - Tank beam:
Lasts for 20 sec after leaving the beam.
Hits Netherspite: Damage taken reduced by 1% per tick.
Hits Player: Netherspite will aggro you.
If no one is standing in the Red Beam, Netherspite uses his standard aggro table.
Damage taken is reduced by 1% per tick.
Defense is increased by 5 per tick.
Health is modified - the first application gives +31,000 maximum health, with additional stacks reducing maximum health by 1000 per stack.
Replenishes full health every tick.

Green Beam Serenity (green) - Healer beam:
Lasts for 10 sec after leaving the beam.
Hits Netherspite: Heals for +4000 health per tick. (Stacking so it heals for 4K, 8K, 12K, 16K etc. -- it is very important not to let Netherspite get hit by this beam.)
Hits Player: Healing done is increased by 5% per tick.
Spell and ability cost reduced by 1% per tick (including abilities that require Rage or Energy, in addition to Mana).
Maximum mana reduced by 200. Stacks up until your total mana pool reaches 0. Druids in Bear/Cat Form will have their hidden mana bars affected as well. Rage and Energy maxima are unaffected.
Similar to the red beam, mana is restored to the new maximum with each tick.
If a Hunter uses Feign Death while tanking the green beam they will become exhausted and not be able to tank it anymore, therefore wiping the raid. (Most Likely)

Blue Beam Dominance (blue) - DPS beam:
Lasts for 8 sec after leaving the beam.
Hits Netherspite: +1% spell damage increase per tick.
Hits Player: Damage dealt is increased by 5% per tick.
Healing received reduced by 1%.
Damage taken by spells is increased by 8%.
Portals will always spawn at the same locations in the room during all Portal phases, but their colors will semi-randomly change each time after the first Phase.

Beam Blocking Assignment

Red Beam - Classes with high armor, defense and health (i.e. Warriors, Bear Druids, Paladins, Shamans and Hunters). The red beam gives them the massive healing and health needed to tank Netherspite. But despite the replenishment to full health every second, Netherspite can sometimes crit them for very high numbers well above 10,000 (even on plate). So leather and cloth wearers can still get easily one-shot despite the augmented health maximum. Resilience from PvP gear is a useful attribute here.

Blue Beam - DPS classes (preferably with high health or shadow resistance). While their damage output increases rapidly, the damage received by them from Netherspite's shadow aura is also rapidly increasing and healing spells on them will become more and more ineffective. Players staying inside this beam for too long are also becoming highly prone to be killed by a Void Zone appearing under them. A Warlock is especially useful here, as he can replenish the health lost through the increased damage from his Life Drain spell.

Green Beam - The "Healer or DPS Beam". Can also be blocked by classes without a mana pool (Warriors and Rogues) and receive no penalties; they will, however, receive the lowered ability cost. A manaless class can stay for a whole beam's duration within the beam and still be used to take their turn blocking the red or blue beam in the following phase, but this is only recommended if you run out of healers. Any healing class with a HoT ability (Druid, Priest) is especially usefull here, as the HoT continues to heal with the increased amount for the whole duration.

Those not blocking a beam will be DPSing, or raid healing.

For each portal phase you need 1 player for the green beam, 1 for the red beam and 2-4 for the blue beam. After this phase those who took the beam in the last phase will not be able to block it again, so every 2nd phase you need someone different for those beams. It is extremely important to plan and memorize who takes which portal beam at which time. Most wipes occur because one player is not at his designated position when he should be and either does not block the beam he is supposed to block or even worse he takes the beam from someone who is then (after the debuff run out) no longer able to block the beam. To make sure no one loses his beam it is as well very important that the current tank will not move Netherspite around.

One idea is to have one healer remain in the green beam for the whole duration and HoT all players in the raid, which can greatly reduce the heal required. After the beam runs out this player has enough time to replenish his mana with potions or spells (Innervate, Shadowfiend). As long as there is no healer in the green beam it is extremely important that someone else is blocking the beam, otherwise Netherspite heals back to full in a very short time. If your healers are too slow, assign someone else to block the beam until the healer has arrived.

It is enough to have 2 tanks for this encounter, as a tank can - after he grabbed aggro through the red beam - move out and back into the red beam to avoid the reduction of health, while he still is healed through the effect of the red beam. With this tactic it is possible for one well equipped tank to hold the red beam for one full phase. If you try this one, make sure that the tank does not move Netherspite when he moves out of the beam, otherwise you risk that all others lose their beam as well.

A good strategy to assign beam blockers for a regular Karazhan raid composition (3 healers, 2 Tanks and extras) could look like this:

Class Odd Portal Phases Banish Even Portal Phases Banish
Healer A
Healer B
Healer C
Tank A Red Beam Green Beam
Tank B Green Beam Red Beam
Melee A Red Beam
Melee B Blue Beam Red Beam
Damage Dealer A Blue Beam
Damage Dealer B Blue Beam
Damage Dealer C Blue Beam

Notice that the first Red Beam blockers of a Portal phase in this example are your main tanks. This is highly advisable, because they should also be the ones to grab Netherspite's aggro after a Banish phase and have to be able to withstand 10 seconds of his melee attacks without the augmentation of the Red Beam.

Healers are entirely unassigned in this example, so that they don't have to bother with locating a portal and moving towards it when they should actually all be concentrating on healing up the raid after a devestating Banish phase. Thus the tank who isn't used to block the red beam in that phase sees after that instead. Healers can still choose to take the green beam from them anytime they find the opportunity and need for it.

Beam Blocker Transition

Players who are setup as beam blockers for the second half of a Portal phase should be positioning themselves in front of the beam blockers of the first half once those have their beam secured. Once these have acquired 25 stacks of the beam's buff, they simply need to move out of the beam to have it hit their successor in front of them.

Banish Phase

The Banish phase lasts about 30 sec:

Netherspite is banished, remains mostly stationary but still vulnerable to all damage.
Netherspite is still able to deal melee damage to you during the Banish phase if you get too close to it. Only tanks should stay in melee range.
Damage from Nether Burn aura will stop and no new Void Zones spawn during this phase.
After a few seconds of inactivity he randomly fires Netherbreath in the direction of a random player, launching a blast at any players standing in an infinite-range cone in the direction he was facing during the cast. The blast inflicts ~4.5k arcane damage, accompanied by a knockback.

Dealing with high damage bursts from Netherbreath becomes another difficult challenge after the raid has learned to cope successfully with beam management. Everyone who does not have a maximum health pool of more than 9000 HP is prone to be killed by two consecutive bolts if the player fails to escape the cone area in time twice in a row. It is mandatory that every player's health is kept above 4,500 HP at all times. Players should use Healthstones or healing potions in response to a failed breath dodge, rather than rely on healers who will often have range problems due to the knockback. It's also possible to use bandages, since the Nether Burn aura is inactive during this phase.

Players should stand very close to Netherspite, unlike other dragons he has no cleave or tailswipe, only melee against the highest threat. This way they can pivot around (or through) him quickly to avoid the direction he's facing during the 2.5 second Netherbreath windup, and evade the attack entirely.

DoT effects should be timed very carefully in this phase, because after 30 seconds Netherspite will unbanish and reset his aggro table which he will go by for the next 10 seconds until someone can block the Red Beam again. The next Red Beam tank should immediately try to gain his aggro (save up some Rage for this during the Banish phase as he can't be taunted) and position himself between the dragon and the next Red Portal.

Miscellaneous Hints
A single tank can handle the red beam for an entire beam phase. He dances in and out of the beam every five seconds to clear Netherspite's -damage% stack and keep his own stack low for a higher max HP. The two tanks can then simply swap between the red and green beams. This simplifies beam management considerably.
No one should ever cross the Red Beam behind its designated blocker. He would temporarily gain Netherspite's aggro who would move in order to reach this player and together with him the Green and Blue beams - which might slip off their respective blockers.

The Green Beam can be temporarily "stolen" from its blocker to gain a few stacks of its buff for its mana regeneration effect. Make sure to move out after you've gained 5-6 stacks or the original blocker will become unable to accept the Beam back due to having gained Nether Exhaustion.

Warriors should never use Berserker Stance when blocking the Red Beam. Netherspite can crit them for up to 30,000 damage if they do so.
Red Beam blockers should be careful when moving out of void zones. It is usually possible to move forward or backward enough to not take damage from the void zone without causing Netherspite to shift position (thereby causing the blue and green beams to shift off their blockers and onto Netherspite). Some people prefer to just sit in the void zone as the red beam's healing ability can usually make up for the extra damage.
Warlocks in the blue beam should cast Curse of Doom at the end of the portal phase when they have many debuffs stacked. It will hit for between 5% and 7% of Netherspite's health.

Shadow Priests can also sustain a full duration of the Blue Beam if they have 2 points in the Improved Vampiric Embrace talent. Since Vampiric Embrace scales with damage done, the reduction to healing effects is offset. This in turn also benefits the Priest's entire group with massive health gains, since the Priest is the only one affected by the Blue Beam.

The three different portals always spawn at the same location in the first Portal Phase:
Red to the right of the entrance
Green to the left of the entrance
Blue opposite of the entrance

During the Banish phase, healers should spread out to cover every side of Netherspite, so that no one ever gets knocked back out of every healers' range. It's a good practice to put raid target symbols on your healers so they can better coordinate their positioning.
Another way to deal with the Banish Phase is to simply have everyone but one healer and one tank move out of range of the Netherbreath, at the back of the room. Netherspite will still attempt to target players that are out of range, and thus will not use Netherbreath as often on the two remaining behind. This requires Netherspite to be tanked at the far front of the room, and the raid will have to be quick to reposition themselves for the next Portal Phase.

This is a safer method but if the raid has low DPS it may be a better idea to maintain dps during the banish phase to ensure a kill before Netherspite enrages.
If you have lots of DPS, yet another way to deal with the Banish Phase is to simply have EVERYONE run out of range of the Netherbreath, at the back of the room. Netherspite will still attempt to target players that are out of range and do nothing. If the tank has a boss timer he can usually get back in time to pick up aggro. Another trick is if you have a shaman drop a Searing Totem when you all run away, Netherspite will try to kill the totem with his Netherbreath(which is an AOE spell). Totems are immune to AOE damage however, so the totem will generate aggro while the raid is at the back at the room, while providing a small amount of DPS. Also it will aggro Netherspite as soon as the banish phase ends providing time for the tank to pick him up.

https://www.youtube.com/watch?v=iBMcaL_t-Ig&feature=related