The Descent Into Madness
General Vezax
"Strange creatures known as faceless ones lurk in the depths of Ulduar. One of their mightest commanders, General Vezax, guards the twisted passages leading to the Prison of Yogg-Saron."
General Vezax has 8.3mil hp in 10man with 30.8mil hp in the 25man version. This fight is a challenge for healers and casters because of the mana issues involved, but with a generous enrage timer playing smart and fighting at a steady pace will overcome the difficulties. The boss is immune to taunts, so start dps slowly and allow the tank to build threat.
Abilities:
Aura of Despair - A permanent aura on Vezax that prevents all mana regeneration and reduces melee attack speed by 20%. This aura also prevents the use of mana pots and mana gems as well as abilities like Innervate and Evocation. (Somewhat still effective however, are Aspect of the Viper, Judgments of the Wise, Shamanistic Rage and Spiritual Attunement)
Shadow Crash - This is a shadow attack that is lobbed at a ranged player and is avoidable. On impact it deals ~12,000 (~6,000) damage to everyone close by and knocks them back. After landing it leaves behind a shadow residue on the ground that can be stood inside of; lasts 20secs. While inside the residue magical damage is boosted 100%, casting time by 100%, healing done reduced 75% and mana costs reduced 75%. This ability will not be cast on anyone within 15yrds of the boss. (Caster dps need to stand in these while casting, healers should avoid them however)
Searing Flames - This ability has a 2sec cast time and is interruptable. When allowed to be used it deals ~14,500 damage to the entire raid and superheats armor, lowering it's ability to protect the person by 75% for 10secs. (This needs to be interrupted every time or it is generally a wipe)
Mark of the Faceless - This ability will randomly target someone 15yds+ from the boss and will siphon 5,000hp/sec for 10secs from anyone within 10yds of the person afflicted. The dangerous part is that Vezax heals himself for 100,000hp for each tick/person this is hitting. This ability is only used on ranged members at least 15yds away, but if there are less than 9(4) people standing 15yds away he can and will use it within melee range. (If you have this debuff you must immediately move away from the raid)
Surge of Darkness - This is a self-buff that takes 3secs to cast and is used roughly once a minute. This buff increases Vezas' physical damage by 100% but reduces his movement speed by 55% for 10secs. (He should either be kited for this portion or cooldown will need to be used as the tank can easily be 1-shot during this)
Saronite Vapors - Roughly every 30secs a green crystal called Saronite Vapor will form and begin floating around the room. In total, 8 will spawn, with the last one spawning about 4min into the fight. They have low health and when destroyed they drop a green residue on the ground that can be stood in. If none of them are killed, the hardmode will be activated. While standing in the residue a stacking debuff will be applied every 2secs. that both regenerates mana and causes shadow damage as follows:
1 Stack 100 mana 200 Damage
2 Stacks 200 mana 400 Damage
3 Stacks 400 mana 800 Damage
4 Stacks 800 mana 1,600 Damage
5 Stacks 1,600 mana 3,200 Damage
6 Stacks 3,200 mana 6,400 Damage
7 Stacks 6,400 mana 12,800 Damage
8 Stacks 12,800 mana 25,600 Damage
The sweet spot for stacks is no less than 5 and no more than 7. Healers will want to get inside of these whenever possible in order to regain some mana. Casters can use them as well, but they are better off sticking to the Shadow Crash residues since using these will cause extra raid damage that needs to be healed. (These should be broken in a controlled amount to fully utilize the buffs when needed most)
Soft Enrage: Surge of Darkness can easily lead to wipes and each one should be treated cautiously.
Hard Enrage: 10min into the fight Vezax will enrage and wipe the entire raid almost instantly.
Adds:
Saronite Animus: This add spawns when all 8 Saronite Crystals have spawned and remain undestroyed. The Animus has 12.4mil (2mil) hp and must be destroyed before finishing Vezax.
Profound Darkness - Deals 750 Shadow damage to the entire raid and increases Shadow damage taken by 10%/stack.
Strategy:
The General Vezax fight is basically a tank and spank encounter with a few twists. The main twist is that mana regeneration is rendered useless for the entire encounter, with the other twist being a short kite phase about once a minute. Unless you are going for a hard mode kill, only 1 tank is needed for this fight. You can keep a second tank as standby in case one dies, but Vezax cannot be taunted, so you will likely lose half the raid before another tank can gain control of the boss. After defeating all of the adds in the room, pull Vezax towards the central area and allow your tank to build some threat before going all out.
When the fight begins, all melee classes as well as most healers should be stacked up within 15yds of Vezax and remain at this distance for the duration of the fight. The rest of the raid should split into two ranged camps (one in 10man) with at least one healer in each group, possibly two. The reason for this split is two abilities: Mark of the Faceless and Shadow Crash will only be used on people more than 15yds from the boss, unless there are fewer than 7 (4) people at ranged distance. You do NOT want these abilities used on melee, so be sure you have enough people at a ranged distance. Shadow Crash is easily avoidable if you are paying attention, and if you gain the Mark debuff you should immediately move away from your camp group.
Aura of Despair will render almost all mana regenerative abilities useless for the entire fight, so don't bother using abilities like Evocation, Innervate or Blessing of Wisdom, nor items like mana pots, gems or totems. The only abilities that do not seem rendered fully ineffectual are Aspect of the Viper, Judgments of the Wise, Shamanistic Rage and Spiritual Attunement. In order to make sure people don't feel left out of the nerfing on this boss, melee attacks speed is also slowed by 20% from this Aura, so a good blend of both dps is preferable. In order to combat the lack of mana regeneration, the raid is left with two residual pools that people can stand in, but both have advantages and disadvantages, as well as actual strategic uses that will need to be planned out ahead of time. The first of these abilities are the Shadow Crash attacks. When cast, this spell is lobbed towards a random player and everyone should move away from that spot in order to dodge the damage it causes. Once it lands, there will be a dark residue left behind for a short while and all ranged casters should quickly stand in this puddle. The residue will cut cast speed in half, double the damage and lower mana costs by 70%, so casters should only be dps'ing while standing in these and begin spamming their direct damage spells. The residue also reduces healing effects by 75%, so healers should NOT use these puddles (the exception being a disc priest that can stand in these and spam shields off). Option 2 comes from the Saronite Crystals that spawn and float around the room. When destroyed, these crystals will drop green puddles on that ground that will grant mana regeneration while standing in them, but also apply a dot that stacks at the same time. Only a total of 8 will spawn the entire fight, about 30secs apart, so use these wisely and make sure healers call it out to have them destroyed only when really needed. Ranged dps can use these as well as healers, but the casters should use them only if absolutely necessary since the damage they take will need to be healed and only wastes more healer mana. The sweet spot for standing in these is about 5-7 stacks of the buff/debuff: any less than 5 is practically useless for healers, but any more than 7 will likely 1-shot them (Shadow resistance effects this DoT as well).
Now that casters know what they have to deal with, there are two more abilities that will need to be discussed. Searing Flames will be cast roughly every 10-15secs throughout the fight and should be interrupted every single time. The spell deals massive damage to the entire raid, which could be healed through, but it also lowers everyone's armor by 75% for 10secs. The damage can be very dangerous, but the debuff is what will likely get your MT killed before the 10secs are over, so melee must always be on the watch to interrupt this cast every single time. The other danger is Surge of Darkness, which Vezax will cast about once every 65secs roughly. When used, this ability will double his damage but slow his movement by 55% as well. The raid has two choices of how to deal with this ability: the MT can begin kiting Vezax for the 10sec duration, or you can cycle tank and healer cooldowns each time this used. Both strats are viable and will depend mostly on your raid composition and comfort level as to which you choose to use.
In summary: always interrupt Searing Flames, kite or use cooldowns for Surge of Darkness, dodge Shadow Crash and stand in it for caster dps, healers get 5-7 stacks of Saronite Vapor, and if you get Mark of the Faceless you need to move away from everyone. Dealing with Mark and Crash is a two-fold strategy. Because of the huge benefit stand in the residue grants, you want all of you ranged dps to be standing in these and only casting when they are. If someone gains the Mark debuff however, they should drop everything and immediately move away from the other casters. The damage the debuff causes isn't horrible, but the 100,000hp/sec/person it will heal Vezax for can kill any chance of beating his enrage timer if people don't pay attention.
Hard Mode:
Letting all 8 Saronite Crystals spawn and remain unbroken will cause them to coalesce into the Saronite Animus. When formed, Vezax will be protected by Void Barrier which makes him immune to damage until the Animus is destroyed.Achievements:
Shadowdodger - Defeat General Vezax without any raid member being hit by Shadow Crash.
Never Stand Near the Faceless Dude - Defeat General Vezax without allowing him to regain health from Mark of the Faceless.
I Love the Smell of Saronite in the Morning - Defeat General Vezax after defeating the Saronite Animus.
Video:
Tankspot VideoYogg-Saron
"Long ago the titans imprisoned Yogg-Saron deep within Ulduar to save Azeroth from the Old God's destructive power. But after years of plotting, Yogg-Saron has succeeded in corrupting its guards, and now the monstrous creature is finally breaking free."
The Old God Yogg-Saron is a 3 phase encounter. The boss has a total of 55mil (11mil) hp and will need to be brought down a certain amount each phase in order to move on. Each of the 4 Keepers of Ulduar can also be asked to help in the fight, with each Keeper adding different effects and abilities to boost the raid's chances of success. Anything less than all 4 is considered a hard mode attempt and there is an achievement for each time you use one less Keeper. In 25man you will need to use 3 or less Keepers in order to forge the legendary mace as well.
All Phases:
Sanity - All players start the encounter with 100 stacks of a buff called Sanity. Different abilities throughout the fight will remove stacks of this buff and when a player's Sanity reaches 0 they will become insane and under the will of Yogg-Saron. While insane, players will be permanently mind-controlled and see all other raid members as Faceless Ones, attacking them. Insane players must immediately be killed off and cannot be battle rez'd as they will still be insane until the encounter is over.
Keepers:
Hodir:
Fortitude of Frost - Increases player size by 10%, damage done by 10% and reduces damage taken by 20%.
Hodir's Protective Gaze - This ability allows Hodir to save someone that takes fatal damage by encasing them in ice. While encased in ice the player will be unable to perform any actions, but they can be healed. The ice lasts 10secs but can also be clicked off early by the player. After using this ability Hodir will require rest, so he is unable to use this ability again for roughly 15secs.
Thorim:
Fury of the Storms - Increases player size by 10%, damage done by 10% and increases total health by 20%.
Titanic Storm - Thorim channels this ability throughout phase 3 and will randomly zap and destroy weakened immortal creatures. This ability is the only way that the Immortal Guardians from phase 3 can be destroyed.
Freya:
Resilience of Nature - Increases player size by 10%, damage done by 10% and increases healing received from all sources by 20%.
Sanity Well - Freya creates Sanity Wells that are green beams of light in the room. Standing inside of one will regenerate lost sanity but lowers damage by 50% while inside of them.
Mimiron:
Speed of Invention - Increases player size by 10%, damage done by 10% and increases movement speed by 20%.
Destabilization Matrix - This is used throughout phase 2 on the tentacles and reduces their attack speed by 100% and their casting time by 300%
Phase 1:
Sara/Yogg-Saron
Abilities:
Sara's Fervor - Cast on a random player, this spell will increase their damage by 20% but also increases the damage they take by 100%; lasts 15secs.
Sara's Blessing - Cast on a random player, this spell will heal them for ~30,000hp but also apply a DoT that deals 60,000 Shadow damage over 20secs.
Sara's Anger - This ability is cast on a random Guardian of Yogg-Saron and applies a DoT that does 12,500 Shadow damage every 3secs but increases their physical damage by 12,000; lasts 12secs.
Adds:
Guardian of Yogg-Saron: These adds spawn only during Phase 1 and must be tanked. They spawn from the orbiting clouds around Sara in an increasing frequency as time goes on and will also be spawned if a player walks into a cloud. They have 950,000 (220,000)hp and are used to destroy Sara.
Dark Volley - Cast randomly this spell will hit the entire raid for ~10,000 Shadow damage and apply a -25% healing debuff; lasts 10secs. (Can and should be interrupted)
Shadow Nova - When killed, the Guardians will explode and deal 25,000 Shadow damage to anyone caught nearby, including Sara (This is the only way to finish Phase 1)
Phase 2:
Sara/Yogg-Saron
Abilities:
Psychosis - Randomly cast on raid members, this instant cast spell deals ~5,000 Shadow damage and reduces Sanity.
Death Ray - Four green beams will appear randomly near the raid and begin moving around after ~2secs. Anyone hit with a beam will be instantly killed.
Brain Link - Links the brains of two random raid members. If these linked players are more than 20yds apart from one another they will take 3,000 Shadow damage and lose 2% Sanity every second until they are back in range. (Beam is yellow when in range and turns red when out of range)
Malady of the Mind - Deals 5,000 Shadow damage and reduces Sanity by 3%, also causes the target to run in terror for 4secs. After the fear effect wears off, the Malady will attempt to jump to another player within 10yds. (If no one is in range the Malady will end, otherwise it can jump endlessly through the raid)
Shadowy Barrier - Protects the body of Yogg-Saron from all damage. (Must bring the brain to 30% hp to end Phase 2 and remove barrier)
Brain of Yogg-Saron:
Induce Madness - Cast on all raid members inside the Phase 2 portals, this ability reduces Sanity by 100%; 60sec cast time.
Adds:
Outside Portal:
Constrictor Tentacles: Highest priority kill in p2; have about 100,000 (20,000)hp.
Squeeze - Grabs a nearby player and squeezes them for 7,500 (6,000) damage/sec. (Cancels Druid shapeshift; highly dangerous to feral tanks)
Crusher Tentacles: 2nd highest priority kill in p2; have about 2mil (400,000)hp.
Diminish Power - Weakens the raid by lowering everyone's damage by 20%. This only applies when the tentacle is not being tanked or hitting someone. (Ability stacks with each Crusher Tentacle spawned)
Focused Anger- Stacking buff that increases damage by 3% every time the tentacle is hit; stacks up to 99x and lasts 1sec. (Stack can fall off after 1sec of taking no direct damage)
Corrupter Tentacles: Low priority kill, kill off when no other tentacles are up; have about 600,000 (100,000)hp.
Curse of Doom - Dooms the target just like the Warlock curse; deals 20,000 Shadow damage after 12secs. (Curse type dispellable)
Apathy - Lowers attack speed, casting speed and movement speed by 60%; lasts 20secs. (Magic type dispellable)
Black Plague - Plagues the target with a retching disease; stuns the person for 2secs every 3secs and lasts 24secs. (Disease type dispellable)
Draining Poison - Deals 3500 Nature damage and drains 1400 mana every 3secs for 18secs. (Poison type dispellable)
Inside Portal:
Influence Tentacles: These tentacles are disguised as NPCs inside the portal and must be destroyed to get to Yogg's brain; have about 40,000 (8,000)hp.
Grim Reprisal - All attacks against these tentacles are reflected back onto their attacker by 60%.
Laughing Skulls: These mobs are stationary and untargetable inside the portals; their only ability is to drain Sanity.
Lunatic Gaze - Looking into the skull's gaze causes 1750 Shadow damage and a 2% Sanity loss/sec.
Phase 3:
Yogg-Saron
Abilities:
Lunatic Gaze - Gazes upon the raid and anyone looking into the gaze will take ~6,000 Shadow damage and lose 4% Sanity/sec as long as they are facing Yogg-Saron. (Seen as a wave of purple beams when used; face away until wave is over)
Empowering Shadows - Applies a buff to the Immortal Guardians that will heal any other add within 20yds for 750,000hp over 20secs. (This can be used on Yogg as well if an add is too close to him when they receive the buff)
Deafening Roar (Heroic Hard Modes Only) - Deals ~8,000 physical damage to the raid and silences for 4secs. (This is when to throw the Shattered Fragments of Vala'nyr into Yogg-Saron in order to forge the mace)
Soft Enrage: None
Hard Enrage: After a total of 15min of combat, Yogg-Saron will cast Extinguish All Life, instantly killing the entire raid.
Adds:
Immortal Guardians: These are the only adds in p3 and you cannot kill them without Thorim's help; have about 500,000 (100,000)hp.
Empowered - Damage is increased by 180% at full health and this ability starts with 9 stacks. Every 10% of health lost will drop a stack.
Drain Life - Drains a random target for 3,333hp for 5secs.
Strategy:
The Yogg-Saron fight is a 3 phase fight that is similar to the Thorim encounter in that after a short phase one, phase two will consist of 2 groups that split off and phase 3 sees the raid re-combine to finish off the boss itself. Yogg himself will remain unattackable until the final phase, using his Sara avatar to fight the party with until the last phase. After breaking the spell Yogg has used to cloud the minds of the his 4 Watchers, they will appear around the Observation Ring. Talking to each of them will allow the raid to ask for their help against the Old God. Be sure to only talk to as many of the Keepers as you desire to have help in this fight: all 4 will be the normal, easy mode while each one less increases the difficulty and allows for more achievements.
Another important thing to watch for that is unique to this encounter is a buff called Sanity. Everyone begins the fight with 100 stacks of Sanity, and various abilities during the boss fight will attempt to remove stacks. If someone is reduced to 0 Sanity they will become Insane and under the control of Yogg-Saron. Once someone goes insane, the raid must immediately kill that player off before they take out a bunch of other people. Someone that has gone insane cannot be battle-rez'd or they will still be Insane until the next attempt. The only way to regain lost Sanity stacks is if Freya is helping the raid by dropping Sanity Wells that can be stood inside.
Phase 1: Sara
The encounter begins as soon as the raid walks into the room, so be sure you are ready to start before heading inside after defeating General Vezax. Sara will be floating above the pool in the middle of the room for the entire phase, and while the raid can target her, you cannot directly damage her. You will also notice green clouds that orbit the central area of the room around Sara, pay attention to these. During this phase, Guardians of Yogg-Saron will spawn from these clouds, starting at roughly 30sec intervals and increasing over time. When you see a cloud begin glowing, a Guardian will be spawning from it in a moment. The tank should pick the add up and hold it next to Sara. Quickly dps the add down and make sure the raid keeps rotating with the clouds while doing so. If someone steps into a cloud, this will also trigger a Guardian spawn, so try to avoid the clouds or you can end up overwhelming the raid with adds. The Guardians will cast Dark Volley frequently and this should be interrupted as much as possible. The damage is decent and hits everyone within 35yds, but it also applies a -25% healing debuff for 10secs which is what you want to avoid. When the add is low in health, all melee dps should quickly move away because on death the Guardians will explode for 25,000 Shadow damage. This is the only way to defeat the Sara avatar and after 8 Guardians explode by Sara, Phase 2 will begin.
While it is highly recommended that everyone avoid the clouds in this phase, they can also be used to your advantage. Once the raid is geared decently and more experienced with the encounter, you can trigger extra spawns on purpose in order to quicken the time taken on Phase 1. This comes in handy when you are trying for the 7min achievement or using few to no Keepers and wish to plow through the initial phase.
Besides the adds you have to deal with, Sara will also be casting spells during the phase. Sara's Fervor will by cast on a random raid member and while it increases the damage they do by 20%, it will also increase the damage they take by 100%. While this generally shouldn't be a big issue, it can cause a wipe if the Guardian tank has this on them during an explosion. Be sure to either use tank cool downs or swap tanks until the debuff wears. Sara's Blessing will instantly heal a random raid member for a large amount, but then applies a DoT that causes another 60,000 damage over 20secs. This is more a nuisance than a threat, so just be sure to keep heals on anyone with the DoT on them. Sara's Anger will boost the damage on a random Guardian add by 12,000 as well as apply a DoT on them that causes considerable damage. After a tank's mitigation is taken into account, the boosted damage is actually very minor, while the DoT effect will actually help the raid burn these adds down faster.
Phase 2: Yogg-Saron's Tentacles
After Sara has been hit with 8 Guardian explosions, Phase 2 will begin. At the start of the phase, Sara will change forms and float into the air, while beneath her Yogg-Saron will appear with an impenetrable field protecting him. Three new adds will also spawn: 1 Crusher Tentacle, 2 Corrupter Tentacles and a Constrictor Tentacle. They will pop out of the ground randomly almost anywhere in the room in a circle around Yogg, dealing minor damage and knocking back anyone close to their spawn location. The adds will not move from their location, and only the Crushers have a melee attack and need to be tanked. The kill priority for these adds is: Constrictor, Crusher and then Corrupter.
Constrictor Tentacles will spawn under random raid members and grab them, roughly every 20secs, dealing decent damage over time until destroyed. The gripped player can still use most of their abilities to help free themselves or keep healing, but will keep taking damage until freed. These have no other attack and have the lowest health of the 3 adds. They biggest danger they pose are to druids, as the grip will pull them out of shape-shifted forms, which can be extremely dangerous if you are using a feral tank.
Crusher Tentacles are the second priority and will spawn roughly once a minute somewhere in the room. They have a large amount of health and cause decent melee damage to a geared tank. The do need to HAVE to be tanked, but whenever they are not being tanked or dealing melee damage to someone, they will use Diminish Power on the entire raid while lowers all damage dealt by 20%. This effect also stacks with each Crusher currently up, so allowing it to stack will cause the raid to slow its damage output considerably. They also have a stacking buff similar to the Snaplasher from the Freya encounter, which increases attack speed and power by 3% for each stack (only direct damage will give a new stack). This stack falls off after 1sec of no direct damage, so the best course of action is to have a tank pick these up and keep it faced away from the raid (it also has a frontal cone attack) while everyone burns it down. When the tank calls for a stop, everyone immediately stops dps'ing the Crusher and the tank backs off for a moment, the stack will drop and everyone can get back on it.
Corrupter Tentacles are the lowest priority and have no melee attacks. They will spawn about once every 30-45secs and only cast their spells on the raid at random. Each of its 4 spells belongs to one family of debuffs: magic, disease, curse and poison. Their spells have an infinite range and will need to be quickly dispelled by the appropriate class. While annoying, they pose little threat compared to the other adds and should only be killed when none of the other adds are up.
During this phase there are an additional 4 abilities used by Yogg-Saron and his Sara avatar. Psychosis will be cast on random people whenever another ability isn't being cast. This spell only deals ~5,000 damage, but also reduces Sanity by a decent chunk. Malady of the Mind will also be used on someone at random, causing minor damage and Sanity loss, but also causing them to flee in horror for 4secs. The danger with this attack is that the malady will attempt to jump to another person within 10yds after being feared, which can lead to a perpetual chaining effect if not careful. Brain Link will be cast on two random people and this ability will cause the two afflicted members to be linked together for awhile. If the link appears yellow, nothing will happen, but if the two players stand more than 20yds apart the link will turn red and both people will take damage and lose Sanity each second until they move back together. The last of the 4 abilities used is the most dangerous: Death Ray. As the name implies, this beam will kill anyone in its path. Appearing as 4 green beams from the sky, they will target random spots on the ground and after ~2secs they will start dragging across the ground, killing anyone that crosses its path.
Phase 2: The Brain of Yogg-Saron
In addition to all of these things to watch for, there's also a portal phase to deal with. About 60secs into Phase 2, portals will appear around Yogg-Saron (10 in the 25man version), with new ones respawning about 90secs later. Each portal used will vanish, so a max of 10 players can enter the brain realm at a time. You will not need a tank for this phase, but you should send in at least 2 (1 in 10man) healers and most of your melee dps. The portals lead to a vision of 3 different places where Yogg-Saron has influenced at some point: the Shadow Vault in Icecrown, Stormwind Keep and the Obsidian Sanctum, with locations chosen at random but never the same one twice in a row.
While inside of the portal you will see various NPCs, these are illusions and when attacked reveal themselves to be Influence Tentacles of Yogg-Saron. They have low health and no attacks, but while killing them they will reflect 60% of the damage received back onto their attacker. The adds will drop quickly, but be sure to wait on a heal if your health gets low so that you don't kill yourself trying to rush. The other thing to watch for here are the Laughing Skulls. They cannot be attacked and will not move from their location, but will channel Lunatic Gaze whenever a person faces them. Because of this everyone in the brain realm will need to navigate through the areas and kill off the NPCs while strafing through the rooms and avoid facing these adds.
Once all Influence Tentacles have been killed, a path will open to Yogg-Saron's brain. In addition, this will cause all tentacles outside the realm to become stunned for a short time. During this stunned phase, no new adds will spawn and all tentacle attacks will cease, giving the group outside a chance to catch up on adds. When the portal group moves into the brain room, they will see the brain has been channeling a spell called Induce Madness, which has a 60sec cast time. The DPS will need to start burning the brain as much as possible before the spell finishes casting. Exit portals will appear inside this area and when Induce Madness reaches ~5secs remaining, everyone should immediately exit the realm. If you are caught inside when this spell goes off, it will instantly remove all Sanity stacks and render the person Insane for the rest of the fight. The brain has roughly 7mil hp and shares a link with Yogg's total health. The goal is to use the portal phases in order to bring the brain to 30% health, which will in turn lower Yogg-Saron's massive health pool of 55mil hp down to a more manageable 16.5mil hp and begin phase 3. You should get to phase 3 after 3 portal phases have been completed.
Phase 3: Yogg-Saron
No new tentacles will spawn in Phase 3, but you should quickly finish off any remaining from Phase 2. If you still have a lot up, burn down any Constrictor and Crusher ones and just deal with the spells the Corrupters cast. As Phase 3 begins, the shell surrounding Yogg-Saron will dissipate and the raid can finally attack the boss himself. Yogg has no threat table and does no melee damage, so no tank is needed on the boss, but you will need some for the adds.
Throughout the rest of the encounter Yogg will spawn Immortal Guardians roughly every 10secs in Phase 3. As their name suggests, these adds are immortal and cannot be killed by the raid. The only way they can be destroyed for good is if Thorim is helping the raid. The adds will spawn at random around the room in a flash of light. They should be tanked and dragged away from Yogg. Assign the melee dps to kill these, as well as a few ranged dps if you don't have enough melee. When they first spawn, the Immortals will have 9 stacks of a buff called Empowered on them, which boosts their damage a lot. Every 10% you lower their health, they lose a stack, which means one tank can hold numerous adds at once if they are at low enough health. If Thorim is helping the raid, he will instantly destroy these adds at low health.
The reason these adds need to be tanked away from Yogg is that he will attempt to heal them at low health and turns them into beacons of healing power. A raid warning will go off when Yogg uses Empowering Shadows on a low health Immortal. This is a HoT that will heal the add and any friendly units (including Yogg) within 20yds for 750,000hp over 20secs. Because of this you need to keep the adds far from Yogg, and if you are not using Thorim for the fight another tank should pull the add with Empowering Shadows away from the rest.
The other important ability to watch for in Phase 3 is Lunatic Gaze. Like the Laughing Skulls in the previous phase, this ability causes damage/sec as well as a loss of Sanity/sec and can be avoided by looking away. The healers should always be faced away from Yogg the entire phase, while ranged dps will need to spin around whenever the ability is used (roughly every 12secs). While turned away from Yogg, the ranged dps can help burn down some of the Immortals until Lunatic Gaze is over. The animation is fairly easy to see as purple "waves" come from Yogg during the attack.
Stay on top of the adds and keep burning Yogg down and eventually the Old God will be defeated.
The Keepers:
All of the Keepers will help tremendously with this encounter, as each one provides much needed boosts. In order to defeat Yogg with less than all 4, it helps to know exactly what each Keeper brings to the table.
Hodir: One of the least important Keepers, Hodir can occasionally save someone from death by encasing them in ice. While this is really nice, it is more of a crutch than an actual tactic and is probably the easiest Keeper to go without using.
Mimiron: His biggest boost comes during Phase 2 as his Destabilization Matrix will drastically lower all of the tentacle's attack and casting speeds. While useful, this is probably the second Keeper to go without using.
Freya: Throughout the fight Freya will drop Sanity Wells that the raid can use to regenerate stacks of Sanity. During the first couple of Yogg fights this is extremely helpful and probably 100% required in order to not lose people to Insanity. As the raid becomes more experienced and incidental Sanity losses become rare, this will be the next Keeper to remove.
Thorim: His only real ability (other than the passive buffs) comes into play at the final phase of the fight. His single ability however, is probably the most important as well. Without Thorim the raid cannot kill any of the Immortal Guardians, and even at low health the raid can be overrun dealing with a ton of adds while trying to finish off over 16mil hp from Yogg. The last of the Keepers to remove, you will need to change tactics in the final phase without his help. The tanks will need to be extremely careful about keeping the adds all occupied, and OTs will need to constantly be grabbing and pulling away Immortals with Shadow Beacon so that they don't fully heal multiple adds at once.
Hard Mode:
Using less than all 4 Keepers activates hard mode, with 0 Keepers being the hardest fight in Ulduar and rewarding a title.Achievements:
Kiss and Make Up - /Kiss Sara in Ulduar while she is angry with you.
Three Lights in the Darkness - Defeat Yogg-Saron with the assistance of three or fewer Keepers.
Two Lights in the Darkness - Defeat Yogg-Saron with the assistance of two or fewer Keepers.
One Light in the Darkness - Defeat Yogg-Saron with the assistance of one or fewer Keepers.
Alone in the Darkness - Defeat Yogg-Saron without the assistance of any Keepers.
Drive Me Crazy - Defeat Yogg-Saron without any raid member going insane.
He's Not Getting Any Older - Defeat Yogg-Saron within 7 minutes.
They're Coming Out of the Walls - Defeat 9 Guardians of Yogg-Saron within 12 seconds.
In His House He Waits Dreaming - Experience all 3 visions of Yogg-Saron's mind.