Northern Sky

C’Thun

And for our final guide we bring you the C’Thun guide, the fight that has caused many arguments and disputes. Here it is for your reading pleasure.

C’Thun phase one abilities:
Eye Beam: 2625 - 3375 nature based spell, functionally similar to chain lightning, in that it jumps from target to target if they are in range of it. For each jump it does, it doubles the damage, resulting in certain death to the people that get hit after the initial target got hit. He casts this spell every 3 seconds.
Dark Glare: 43750-56250 Shadow damage any players that get struck by this spell will with a 110% certainty die.
Eye Tentacles: 45 second spawn timer, spawns at the edge of the dark mist around C’Thun, knocking any targets on their spawn point; casts mindfly (channelling spell), 750 shadow damage per second, in addition slowing the targetted player.

Claw Tentacles: Random spawn over the entire area during phase one. They have approximately 2000Hp in addition hitting any targets in melee range for 200-300 damage.
Ground Rupture: If emerged under players; will case a knock back effect and damaging the targets for 1350 - 1650 damage

Entry to the room:

Because C’Thun’s ability to target players outside the room and even hit them through walls we’ve chosen to have an evenly spread out raid along sides of the entrance, with minimal distance to each other flowing into the room once the encounter has started.
Some people like to send in 1 player ahead of everyone else due to C’Thun targeting him as initial aggro, which gives the raid approximately 3 seconds to run in and spread out. This works fine, but is also more risky and suits players used to the fight. Which you're probably not, if you're reading this!
On the other hand there is a flaw with our "safe" way of doing it aswell, if the raid doesn’t flow in to the room fast enough, C’Thun might start casting dark glare at the entrance killing the last people that are trying to get into the room, but the death rate is far less this way and as players get the entry speed correct it will no longer be a problem.
Have two paladins (or if none available) / two player with high nature resist take the lead of each side of the line, let them drink a greater nature protection potion, priests shield them and have them run in. We chose paladins due to their survivability, if they get low on health, they can just put on their shield and get into position.
After the initial hits on the people that run into the room, C’Thun will start targeting people outside the room; if everyone has a greater nature protection potion on them that they drank before the start of the encounter, everyone should be able to get into the room, get into position without taking a single point of damage. If people are positioned correctly, the Eye Beam will not do significant amounts of damage and players can whipper / bandage; but when learning the fight drink the pots.

Positioning:

Due to the layout of the room and the amount of eye tentacles spawning during this phase, we decided to split up the raid into 8 sections, meaning 5 players in each section of the room. Each group's duty when they are not damaging C’Thun or trying to avoid the dark glare is to interrupt and kill the eye tentacles that spawn in their sector as fast as possible, they don’t have a lot of HP so they go down really fast.
Each group normally consists of two healers, one melee, one ranged, and the fifth member either a healer, melee or ranged. This setup is made so that the use of the space in the room is optimal making sure that the players aren’t close to each other so that they don’t chain the Eye Beam.

In the picture one section of the room has the general positions to which each group/section should try to stick to, to make sure they are spread out enough :

The Fight:

As stated in C’Thun's abilities the Eye Tentacles will spawn each 45 seconds, at which time all the DPS should stop hitting C’Thun and do anything within their power to bring down those eye tentacles as fast as possible. If they are not killed they will most certainly wipe the raid, and if not killed within 45 seconds an additional round of them will spawn and you will have two of them in the same location. These eyes are priority number one for the entire raid, kill them ASAP. We cannot stress this enough, even if 1.5 sec into a 2.5 sec damage spell cast, interrupt it and kill the Eye Tentacles. Immediately.
While this is happening approximately every 90 seconds C’Thun will start to cast Dark Glare, aimed at one of the eight sectors shown in the positioning picture. Everyone needs to keep their eyes on C’Thun - this cast is initiated by him swirling a dark cloud in front of his pupil, at which the group affected needs to start running away from that sector.
Each group has a primary sector and a secondary one, the primary one is the location where the players should run to once they enter the room; the secondary sector is located 180 degrees around the room, placing it in the opposite side of the room. So, for example, sector 4's alternate position is sector 5, sector 8 alternates with sector 1, and so on.
Once the Dark Glare has been initiated C’Thun will rotate 180 degrees around the room, still casting, and then he will stop casting the spell and go back to casting Eye Beam. At this point everyone in the raid should be at their secondary positions until the time comes for the second Dark Glare, at which you should move back to your primary position.
In addition to all of this the Claw Tentacles will spawn randomly throughout the entire room, taking up precious space; have any class with DoT capabilities put a few on them, it should bring them down quite fast due to their lack of HP. Instant casts from mages and melee hitting them as they run past all help.
Also, keep in mind when you are running to your secondary or primary position, you should keep a good distance from the Dark Glare - it might seem harmless when you are running behind it, but all it takes is one claw tentacle to spawn under you knock you into the Dark Glare and you are dead. Mages can Blink through the beam, this can be used to kill leftover Eye Tentacles with great effectiveness if the player is careful.
Once your raid is drilled into this phase it shouldn’t be that hard to complete it with minimal casualties. It is very important for everyone in the raid to survive phase one because every single person counts in phase two.

Phase two:

Once you have reduced Eye of C’Thun’s Hp to 0 his eye will implode and the God himself will appear. C’Thun doesn’t have any abilities except the fact that he is immune more or less to any type of damage, any type of damage caused to him will do 1-20 points of damage, so it’s pointless hammering him - besides, at this point you will have your hands full with other things.

Giant Claw Tentacle: Identical to the Claw Tentacle that spawns during phase one, the only difference is that they do double the damage, and they have increased in size by 400%. This means that you will get a ground rupture for 3000-4000 damage, and their melee hits are for 2500-4500 damage. In addition it uses Ground Tremor, which will cause the targets in a 5 yard area to fall to the ground and get stunned for two seconds.

Giant Eye Tentacle: This Giant Eye will start spawning during phase two; it has the Eye Beam capabilities same as the Eye of C’Thun. In addition it only has 40000Hp and may be stunned and silenced.

Eating Tentacle: This Tentacle can’t be targeted nor harmed in any way, it will spawn under a random target in the raid eating him and sending him into the belly of C’Thun.

The fight:

Before going any further into the description we need to set a few priorities in order to get this working. These priorities are:

Eye Tentacles
Giant Eye Tentacle
Giant Claw Tentacle

Everyone should keep this at the forefront of their mind during phase 2 attempts, and re-assess it constantly. Since C’thun himself isn’t doing any direct damage to the raid, the Tentacles takes priority (set based on how dangerous they are to the raid). Everyone in the raid should keep the position they are in when the Eye of C’Thun is dead, depending on where you are it should be either your primary or your secondary position.
Due to the Giant Claws and Giant Eye Tentacles not having fixed positions, heres a picture of a random placement of a Giant Claw and Giant Eye Tentacle and because of the priority list the dps is on the Giant Eye Tentacle :-

The first thing that will happen is a Giant Claw Tentacle spawn; at this point have the closest tank charge it and all disposable DPS should go at it and bring it down as fast as possible. While this is being done, one or two people in the raid will be swallowed into the belly of C’Thun, where they will find two Flesh Tentacles - these are harmless for ranged DPS since they are immobile and only have a basic melee attack that does 1000-2000 damage. The people that get swallowed into the belly (depending on what class they are) should stay in there as long as possible and do as much damage as they can to those two, they are the key to weakening C’Thun.
We try to have as much ranged DPS as we can in there along with one healer if possible - tanks should instantly run out again. As in all end-game fights communication is of the essence; once you are inside the stomach you will receive a DoT called Digestive Acid that will be automatically removed upon exiting the room. This Dot does around 150 damage every 5 seconds, and will stack on you 99 times. A normal well geared player can handle about 10 stacks of it before running out, which brings us to a key factor in the fight - cycling through and prioritising who should be in or out of the stomach.
For example, if a Priest is already in the belly and another healer (Druid maybe) zones in it is that Priests' duty to tell the Druid before him to get out and take over the position of healing the people inside. Everyone (including the ranged DPS) should start heading out when the digestive acid hits around 8-10 stacks, it is essential not to die in there, loss of people in this phase could cause the loss of the fight. Rogues should (if they have the Evasion ability up) activate Evasion and do as much damage as they can before running out. The way out of the belly is on the island inbetween the two Flesh Tentacles; you only need to step on it and you will be shot out taking 1000 damage on your way, once out you’ll find yourself somewhere along the edges of the room.

Having covered the stomach part we go back to where we were outside. You should have enough time to bring down the first spawn of the Giant Claw Tentacle before anything else spawns; if the Eye Tentacles should spawn before you killed it everyone should switch priority to the Eyes, leaving the tank (and his off-tank) with two healers on the Giant Claw Tentacle. It is imperative to have an off-tank on the giant claw if available, in case the tank should get eaten - an un-tanked Claw Tentacle will despawn and respawn somewhere else in the room causing Ground Ruptures and possibly killing people it hits. The healers should make sure they keep their distance to the Giant Claw Tentacle in order not to get interrupted.
This fight is all about controlling the spawns of the Tentacles and having a co-ordinated raid that knows the priorities. To explain this a bit better we will explain an extreme scenario:
C’Thun is weakened; a weakened state lasts 45 seconds, at which point the Flesh Tentacles in his stomach will re-spawn and you’ll need to kill them again in order to weaken him again.
You have 8 Eye Tentacles up, along with one Giant Eye Tentacle and one Giant Claw Tentacle.

Everyone needs to keep calm once C’Thun is weakened, because in that state no Tentacles will respawn; everyone should have the three priorities in mind - kill the Eye Tentacles while having a few rogues and mages stunning or counterspelling the Giant Eye Tentacle. Once the Eye Tentacles are dead move on to the Giant Eye Tentacle and kill it, and now you may damage C’Thun for what time is left in the weakened state while the tank, off-tank and the two healers are keeping the Giant Claw Tentacle occupied.
An even more extreme situation that may occur if things get out of hand is the same scenario as above, only you have an additional Giant Claw Tentacle, in which case you should bring down one of them before damaging C’Thun.
While things like this are happening, you need to keep in mind to be spread out as with phase 1 once a Giant Eye Tentacle spawns; also remember your positioning in relation to people running around to get the optimal DPS on the tentacle that spawns - this doesn't happen in phase 1, and your raid needs to adjust. Healers should make good space available for DPS to move around when they have the option to do so. You also need to keep in mind that the Eye Tentacles will spawn soon, which means that you need to have either a class that can keep it occupied in each sector or a DPS class that can make a short story out of it.
Summary: Everything in the room in phase two should be killed as fast as possible, in the priority order above, with the exception of one Giant Claw Tentacle which should be killed if the opportunity presents itself.

This concludes our guides in AQ40. We hope that you’ll enjoy this place as much as we did, and wish you the best of luck.

Source: http://wow-inner-sanctum.org/Web/forums/9048/ShowPost.aspx