The Siege of Ulduar
Flame Leviathan
"This massive armored tank guards the courtyard entrance in Ulduar. The Watcher Mimiron constructed Flame Leviathan as part of his V0-L7R-0N weapons platform."
Flame Leviathan has 70mil hp in heroic and 15.5mil hp on normal. The fight is the same in both versions and requires the use of vehicles. As such, raid composition doesn't really matter, but ilvl on gear DOES have an effect on the vehicle's health and damage, so it may be beneficial to place your best geared people in Siege Engines and Demolishers.
Abilities:
Flame Vents - This is a 10sec channeled spell that causes ~3,000 damage/sec to all vehicles and players within roughly 50yds of Leviathan. (Siege Engines should interrupt casting with Electroshock and Choppers should stay away)
Battering Ram - This ability is used to ram Leviathan's target, knocking them forward and dealing damage. It will also apply a debuff that causes 100% damage increase. (When this ability is used, the vehicle being chased needs to use their speed boost to move further away from Leviathan to lessen damage received)
Gathering Speed - This ability is used at random and will increase Leviathan's speed by 5%, stacking up to 20x for a 100% speed increase. Causing a Circuit Overload will reset the stacks to 0. (This ability serves as a kind of soft enrage as well, though there's an achievement for ignoring it)
Missile Barrage - Throughout the fight Leviathan will launch missiles into the raid every 1-2 seconds causing ~700 damage to vehicles and players not in vehicles.
Soft Enrage: Gathering Speed makes the encounter much more difficult to survive but can also be reset with Circuit Overload.
Hard Enrage: None
Adds:
Plant adds when Freya's Tower is left up only.
Vehicles:
There are 3 vehicles in the encounter and each can carry a passenger, but the Choppers should only carry a driver until needed. In 25man there are 5 of each vehicle (10+10+5 = 25) and in 10man there are 2 of each vehicle (4+4+2 = 10).
Salvaged Siege Engine: This is the "tank" vehicle and will be responsible for taking most of the damage, interrupting casts, and taking out towers.
Driver Abilities: Ram - Instant cast, 15yd range, 4sec cooldown. Rams enemies in front of the Siege Engine for ~25,000 damage, knocking them back. Deals ~3,000 damage to buildings.
Electroshock - Instant cast, 10sec cooldown. Shocks all targets within a 25yd cone in front of the Siege Engine, also interrupts spell casting and locks that spell school for 4secs.
Steam Rush - Instant cast, 15sec cooldown. Causes the Siege Engine to go into overdrive, rushing forward and knocking back enemies; deals moderate damage to both enemies and towers.
Passenger Abilities:
Anti-air Rocket - Instant cast, 0.25sec cooldown, 1000yd range. Fires an explosive missile directly forward, detonating when it has travelled 100 yards, hitting any enemies within 10 yards and dealing ~15,000 damage.
Fire Cannon - 10-70yd range. Fires a cannon blast that does variable damage depending on accuracy. Does ~50,000 damage to enemies and ~2,300 damage to buildings.
Shield Generator - Instant cast, 1min cooldown. Absorbs a limited amount (~100,000 damage) of Physical, Fire, Frost and Arcane damage taken for 5secs.
Salvaged Demolisher: This is the slowest moving vehicle but also the source of your heavy dps in the fight. Demolisher drivers have a 50 energy bar which does not regenerate ("energy" = pyrite ammo). Be sure to stock up on pyrite before the boss.
Driver Abilities:
Hurl Boulder - 10-70yd range, instant. Hurls a massive boulder into the distance, dealing ~30k damage to enemies within 8 yards of the target.
Hurl Pyrite Barrel - Uses 5 Pyrite, 10-70yd range, instant. Flings a ball of flaming pyrite into the distance, dealing ~60,000 damage on impact and applying a stacking DoT effect that deals 12,000 damage per second per stack to the target. It stacks up to 10 times.
Ram - Instant cast, 4sec cooldown, 15yd range. Rams any enemies in front of the demolisher, dealing ~9,000 damage and knocking them back. Also deals 2-5k siege damage to buildings.
Launch Passenger - Launches the Demolisher's passenger into the air if they are loaded into the catapult.
Passenger Abilities:
Mortar - Fires a miniature explosive blast, dealing ~11k Fire damage to all enemies in the target area and can ignite tar. 1 sec cooldown.
Anti-air Rocket - Instant cast, 0.25sec cooldown, 1000yd range. Fires an explosive missile directly forward, detonating when it has travelled 100 yards, hitting any enemies within 10 yards and deals ~15k damage.
Grab Crate - Target pyrite crates on the ground and this tosses out a hook that grabs the crates and loads the pyrite as ammo.
Increased Speed - Injects liquid pyrite into the engines, increasing movement speed by 100%. Lasts 20 secs and costs 25 energy.
Load Into Catapult - Load yourself into the catapult arm, using yourself as ammunition. 30 sec cooldown.
Salvaged Chopper: Light dps and low health, but moves very quickly and helps setup tar traps for mobs and the boss as well as pick up the players launched onto Flame Leviathan when they parachute down.
Driver Abilities:
Speed Boost - 50 Energy, no cooldown. Fires the fuel injectors on the bike, increasing its speed by 100% for 5 sec.
Sonic Horn - 20 Energy, no cooldown. Sends a wave of force in front of the motorcycle, causing ~7,000 damage to all enemies in a 35yd frontal cone.
Tar - Drops a pool of tar for 45 sec that slows the movement speed of enemies within 10 yards. Tar can be ignited. Lasts for 45 sec. 15 sec cooldown.
First Aid Kit - Heals your passenger fully over 4 sec. 1 min cooldown.
Passenger Abilities: None
Strategy:
The Gauntlet
Most of the trash mobs are easily taken out by the vehicles and pose no real challenge other than a speed bump on the way to the first boss of Ulduar. The big groups of iron dwarves can be aggro'd by the Choppers, who can then lay down tar in their path to slow them down. The tar can then be ignited and the mobs quickly burned down. The Demolishers and Siege Engines should destroy all the towers and buildings on the way through the Gauntlet as these will continuously respawn trash until destroyed. While fighting your way through, also be on the look out for helicopter mobs that will need to be taken out with anti-air attacks and other gyro-copter mobs that carry pyrite should be destroyed to build up ammo for Demolishers.
On the way through the Gauntlet you will also encounter Iron Colossus mobs that are giant iron dwarf constructs. These adds can use a Ground Slam ability that does high damage to all vehicles around it. Be sure to use Electroshock on these mobs while they are casting to interrupt the ability. Also be on the look out for large mechanical spider mobs that shoot lasers at the vehicles. Be sure to focus fire these mobs down as soon as they appear.
At the end of the Gauntlet you will come to a courtyard and a large gate that is closed off. On the sides of the Gauntlet area at this location are two large, green glowing pads on the ground; running over them will fully repair your vehicles (avoid these if going for the achievement however). Pull the last few groups of mobs until there is only one Iron Colossus mob remaining by the gate. When ready, repair to full and pull the final trash mob. Once he falls, the gate will open and the Flame Leviathan will emerge to defend the gates of Ulduar. This also raises force fields that span the final towers behind the raid, so be sure everyone is in front of the towers before Flame Leviathan emerges.
The Flame Leviathan
This boss is a massive mechanical tank construct, created by Mimiron. During the fight he will randomly choose a vehicle to attack and follow for 30secs at a time. The vehicle can be either a Siege Engine or a Demolisher and Flame Leviathan will follow and attack that vehicle exclusively for 30secs, using Battering Ram to increase the damage it can cause. When Leviathan chooses a target, a raid warning will go off with the person's name that is driving the vehicle. That person should immediately begin kiting Leviathan away from the rest of the raid, using a speed boost when needed so that they can stay ahead and avoid the increased damage as much as possible.
While the boss is being kited, he will also randomly use Flame Vents (usually twice between each target switch) and this should be interrupted by a Siege Engine that isn't currently kiting the boss with Electroshock. Choppers should move far away during this attack until interrupted as well.
In 10man the raid should consist of 2 Siege Engines, 2 Demos and 1 Chopper. One of the Demos will carry two passengers, with one of them pre-loaded into the catapult before the fight begins. The two passengers should be caster dps, as they will be shot onto FL one at a time and need to destroy both turrets. In 25man the raid should consist of 5 Siege Engines, 5 Demos and 3 Choppers. Two of the Demos will carry an extra passenger just as in the 10man version, but these should all 4 be caster dps that can also keep themselves healed such as Moonkins, Ele Shamans, SPriest and Locks.
Siege Engine Driver: Other than kiting FL, all you should be doing is following just close enough to Electroshock whenever he uses Flame Vents. Do not try to dps FL with ram attacks; this puts you in too close of proximity and the added damage is not worth the risk.
Siege Engine Passenger: Primary job is keeping pyrite on the ground with Anti-Air Rockets. Use shield when driver requests and fire Cannon when FL is in Shutdown mode.
Demolisher Driver: Primary job is keeping 10 pyrite stacks on the boss as much as possible and try to stay near areas with lots of pyrite on the ground for your passengers to pick up. If you are driving a Demo that is launching people you must get them onto FL as quickly as possible after FL comes out of Shutdown modes.
Demolisher Passengers: Primary jobs are keeping pyrite on the ground with Anti-Air Rockets and loading them with Grab Crate at all times. Only use speed boost if absolutely necessary since it requires 1/2 the total ammo when used. If you are being shot onto FL, do not load yourself into catapult until the other passenger is almost back to the Demo. Loading early causes the driver to be unable to dps and pyrite stacks are lost.
Chopper Drivers: Do not dps FL and do not stay close to him. Your primary responsibility is to drop tar in FL's path whenever the cooldown is up and pick up the Demo passengers after Shutdown and return them to their pilots. Use the First-Aid Kit on the passengers on the way back to the Demo and just drive right into the other vehicle; the passengers can hop from Chopper to Demo without getting out first. If Freya's Tower is left up you will need to keep tar in the central area and aggro/kite the adds across burning tar so that they do not kill off the other vehicles.
Repeat this process until the tank is destroyed. Once defeated, the gates will remain open and a new teleport is unlocked at the Colossal Forge.
Hard Mode:
Activating Hard Mode for this encounter requires you to speak with Lore Keeper of Norgannon BEFORE speaking with Brann to start the event. When you talk to the construct you are able to activate secondary defenses; this will turn on all 4 defense towers in the Gauntlet area. Each tower is off the path to Leviathan but if you want the hardest setting you can just head straight for Leviathan. Each tower you destroy will lower the difficulty and taking out all 4 will return the raid to "easy" mode. The towers are marked on the map and each one has extra abilities that will add to the fight against the boss if left alone as well as boosting Flame Leviathan's health by 40% for each tower left up.
Tower of Storms:
Thorim's Hammer - Buffs FL's physical damage by 25%. Blue beams of light will begin spawning in the area and drop lightning charges. When the charges hit the ground, they deal about 10% damage to any vehicle too close and 1% damage to the entire raid.
Tower of Flames:
Mimiron's Inferno - Buffs FL's fire damage by 50%. A red beam will begin from where FL enters the area and start dropping fire in a diamond pattern across the floor, moving clock-wise throughout the fight. Being hit by a dropping fire or driving through one will deal a large amount of fire damage and applies a short DoT effect.
Tower of Frost:
Hodir's Fury - Light-blue beams will begin spawning throughout the fight and move across the area. When they get close to a vehicle they will start chasing after them and then stop. Once the beam stops it will begin dropping an ice cluster. When the beam stops you need to drive straight forward or back out of it, turning at all will slow you down too much. If struck with ice the vehicle will take heavy damage and be trapped in a block of ice, taking 1% damage/sec until dead or freed with a fire attack.
Tower of Life:
Freya's Ward - Decreases fire damage done to FL by 10%. Four green beams will spawn, one in each corner. Throughout the fight plant adds will spawn and chase after vehicles, dealing moderate damage.
Like the Sartharion encounter, each tower left alive will add their power to the fight, and there is an achievement for leaving 1, 2, 3 and 4 up at the same time. Leaving 1 tower up will reward an extra emblem; leaving 2 towers up will reward 2 emblems, a recipe and a Runed Orb; leaving 3 towers up will reward 3 extra emblems, a recipe and a Runed Orb; leaving up all 4 is the true Hard Mode and rewards an extra ilvl 239 (232) drop, plus 3 emblems, a recipe and a Runed Orb.
Achievements:
Dwarfageddon - Destroy 200 (100) Steelforged Defenders in 10 seconds on the Ulduar gauntlet.
Unbroken - Defeat Flame Leviathan on the first try without anyone repairing their vehicle.
Three Car Garage - Defeat Flame Leviathan while in each of the following vehicles (Siege Engine, Demolisher, Chopper).
Take Out Those Turrets - Destroy a Flame Leviathan Defense Turret.
Shutout - Defeat Flame Leviathan without causing a System Shutdown.
Orbital Bombardment - Defeat Flame Leviathan with 1 Orbital Defense System active.
Orbital Devastation - Defeat Flame Leviathan with 2 Orbital Defense Systems active.
Nuked From Orbit - Defeat Flame Leviathan with 3 Orbital Defense Systems active.
Orbit-uary - Defeat Flame Leviathan with 4 Orbital Defense Systems active.
Video:
Tankspot 4 Tower VideoIgnis the Furnace Master
"Like the other titan creations in Ulduar, Ignis now serves the Old God Yogg-Saron. This imposing fire giant toils over the Colossal Forge, creating the iron armies that will conquer Azeroth in Yogg-Saron's name."
Ignis looks similar to the 2nd boss in Halls of Lightning and guards a large fire in the outside area of Ulduar. In 25man he has 19.6m hp and 5.6m hp in 10man. Because of how hard he hits the tank with melee, he will not attack faster when he parries. He also summons a Construct every 30secs in heroic but in 10man he uses this every 40secs instead.
Abilities:
Scorch - Fires a jet of flame, burning all enemies in front of the caster within 30 yards, dealing ~4,000 (~2,500) Fire damage every half-second for 3 sec. Additionally, the ground is scorched by this effect causing it to catch on fire, dealing ~3,200 (1,900) Fire damage every second to all enemies within 13 yards. Iron Constructs within this radius will begin to heat up, eventually becoming molten. (Only the MT should be hit with this attack)
Flame Jets - Stomps the ground causing geysers of flame to erupt under all enemies. These geysers deal ~9,000 (~6,000) Fire damage, knocking the targets into the air and interrupting any spells being cast for 6 sec. In addition, the targets take 2,000 (1,000) Fire damage per second for 8 sec. 2.7 sec cast. (All casters MUST stop casting when this is about to go off)
Slag Pot - Charges and grabs a random enemy target, tossing them into the caster's slag pot. The target is unable to attack the caster and takes 6,000 (4,500) Fire damage every second for 10 sec. If the target survives, they are imbued with the magical slag, increasing their haste by 150% for until canceled. (Person in pot must be healed through for 10secs, just like Illhoof's Sacrifice)
Activate Construct - Activates a construct every 40 seconds in normal, and every 30 seconds in heroic.
Strength of the Creator - Increases Ignis' damage by 15% each time an Iron Construct spawns. Stacks up to 99 times.
Soft Enrage: Strength of the Creator acts like a soft enrage. If you get overwhelmed with adds, your tank will eventually be 1-shot.
Hard Enrage: None
Adds:
Iron Constructs - These mobs line the hallway that Ignis is fought in. During the fight he will activate them one at a time. They have like 3-4mil hp so should not be fought, and for each one alive Ignis will gain a 15% damage boost.
Heat - When a Construct is dragged over a Scorch effect, the following happens: Blasts all nearby Iron Constructs with intense heat, increasing their movement speed by 5 and haste by 5. This effect stacks up to 20 times. If this effect stacks to 20, the affected Iron Construct will become Molten.
Molten - The Iron Construct becomes Molten, increasing haste by 100%. In addition, Flames erupt out from the caster every second, dealing ~2,000 Fire damage to enemies within 7 yards. Drag the Construct in the water and it will become Brittle.
Brittle - The cold water causes molten Iron Constructs to rapidly solidify, rendering them unable to act. In addition, if they are dealt more than 5000 damage (in one attack) during this state, they will shatter, dealing ~20,000 damage to all enemies in a 10 yard radius.
Shatter - Deals 18850 to 21150 Physical damage to all enemies within 10 yards. Damage from this effect ignores armor.
Strategy:
This fight can be rather complex to understand at first, but the basic mechanics are easy to figure out. Once multiple Constructs are spawned however, the fight becomes much more intense, and the healing on this can be a huge hassle as well since there is massive raid healing going on as well as the MT taking brutal swings from Ignis, not to mention the Slag Pot attack that will need dedicated healing also.
The fight begins by pulling Ignis from in front of his furnace and moving him towards the central area where the two fountains are located. The MT should keep Ignis faced away from the raid at all times. All of the healers and ranged dps should be able to stay in the middle of the room between the fountains and the MT will move Ignis to the 2 corners of the fountains on both sides of the room (think of tanking at the 4 corners of a rectangle). As the tank moves Ignis across the room, they should strafe sideways and keep Ignis facing outside of the rectangle. Casters must always be aware of what Ignis is doing so that they can stop casting during Flame Jets in order to avoid being locked out of their spells for 8secs. Healers being locked out can quickly lead to a raid wipe.
When the Constructors start becoming active, a dedicated OT will need to pick them up and drag them to Scorch marks. Standing in these will do a lot of damage to the OT, so they need to somehow lead a Construct into one without standing in it themselves. Once a Construct is inside they will need to be rooted, Druids being the best for this purpose, but any snare should work. Once a Construct becomes Molten they should be dragged to the nearest fountain to become Brittle. At this point the OT should move away and call out for the add to be killed; a ranged dps like a mage or lock works best for this since they can do a single cast spell that should do well more than the needed 5k to destroy the Construct.
Rinse and repeat until Ignis is defeated.
Optional Zerg method:
Hard Mode:
NoneAchievements:
Shattered - Defeat Ignis the Furnace Master after shattering 2 Iron Constructs within 5 seconds.
Hot Pocket- Survive being thrown into Ignis the Furnace Master's Slag Pot.
Stokin' the Furnace - Defeat Ignis the Furnace Master in 4 minutes.
Video:
Tankspot VideoRazorscale
"Previously known as Veranus, this creature was captured by Loken and twisted into a vicious weapon. Under Loken's orders, Ignis the Furnace Master fused iron plates onto Razorscales' scales to enhance her deadly strikes."
Razorscale is an Ironbound proto-drake that flies over Razorscale's Aerie, across from the Colossal Forge. It seems Razorscale is the product of Loken's plans with Veranus (Thorim's mount that was captured by Loken during the Sons of Hodir quest chain).
In 25man Razorscale has 12.6m hp and must be brought down with the use of 4 turrets (similar to the fight against Skadi in Utgarde Pinnacle). In 10man she has 3.9m hp and only 2 turrets are needed to bring her down.
Abilities:
Fireball - (Air Phase only) Inflicts 11-12k Fire damage to an enemy. (Constant raid healing)
Devouring Flame - (Both phases) Spits a Lava Bomb at an enemy, inflicting ~7,800 - 9,100 Fire damage and deals 9-10k (6-7k) fire damage every 1 second to anyone staying within 6 yards of the impact, lasts 25 seconds. 1.5 sec cast. (Targets nearest enemy to her, move when cast and stay out of blue fires)
Wing Buffet - 1.5-second cast that knocks players back in a 35-yard radius around Razorscale. (Basically nothing to worry about)
Flame Breath - 2.5-second cast that inflicts 17-23k (13-17k) Fire damage to players in a 50yd cone in front of Razorscale. (Don't stand in front of her, should only hit the MT during phase 2)
Flame Buffet - (Ground Phase only) Increases the Fire damage a player takes by 1,500 (1,000) for 1 minute. Stacks up to 99, but can be dispelled. (Can be a soft enrage if not dispelled)
Fuse Armor - (Ground Phase only) Reduces the armor, attack, and movement speed of an enemy by 20% for 20 seconds. Stacks up to 5 times. (Requires tanks to switch off on tanking during Phase 2)
Soft Enrage: None
Hard Enrage: After 10min Razorscale will go Berserk, increasing attack speed by 150% and damage done by 900%.
Adds:
Dark Rune Guardian - Dark Iron Dwarf that attacks with melee attacks; lowest kill priority.
Stormstrike - Instantly attacks with both weapons. Applies a magical debuff on the target that increases nature damage taken by 20% for 12 seconds. Should be dispelled. (Should only hit the tank)
Dark Rune Watcher - Dark Iron Dwarf that attacks with both melee and nature spells. Single target dps should focus down and stun/interrupt Chain Lightning casts; high kill priority.
Lightning Bolt - Single target nature damage, deals 8-12k damage.
Chain Lightning - Deals damage to 5 targets, each successive hit increases damage. (Stun/Interrupt this)
Dark Rune Sentinel - Dark Iron Dwarf that attacks with melee. Very tall compared to the other mobs, easily distinguishable and should be tanked alone away from the raid; highest kill priority with ranged attacks only.
Whirlwind - 30-40k physical damage on cloth. Only a tank should be hit with it.
Strategy:
Air Phase
During this phase the raid must defend the Expedition Dwarves while they repair the harpoon turrets near the stairs. As the harpoons are repaired they can be used to shoot Razorscale which will pull her towards the center of the ring. When all 4 (or 2 in 10man) harpoons are fired, Razorscale will be pulled to the ground where she can be attacked. Once she is brought to 50% health she will remain on the ground for the rest of the encounter.
While Razorscale is in the air, Dark Iron dwarves will continuously spawn from mole machines that break through the ground out past the circle. The easiest way to deal with them tends to be grouping them up and AoEing them all down. There are a number of ways to handle this part of the fight and it will boil down to raid composition and what the group feels most comfortable with.
Divide and Conquer Method:
The raid can be divided into 2 or 3 groups (10man vs 25man) and take up positions on the back center and sides of the circle, dealing with 1 mole machine group each. When splitting up this way each group will have a tank, some healers, and equal amounts of dps. The tanks will gather their adds while the Watchers should be focused down and the remaining Guardians AoE'd down (or AoE them all and have 1 person watch for Chain Lightning attacks). The tank in the back center of the circle will need to watch for Sentinels and his group should move away while everyone focuses on burning down that add.
Roam and Gather:
In this method one tank will hold all of the adds off to the side of the circle while the other tank(s) runs around gathering up all the adds that spawn at the 2 other mole locations and bring them to the AoE tank. Melee should focus on the Watchers and interrupt Chain Lightning while everyone else AoEs down the entire group. One tank should also be watching for Sentinel spawns and call out when they are up. All ranged dps will need to focus fire the Sentinels down immediately and the tank on them should stay away from the rest of the raid to avoid hitting people with Whirlwind.
Either method chosen is fine, but remember killing priority on the adds is as follows: Sentinels > Watchers > Guardians
While killing the adds the turrets will be repaired one by one. After the 3rd turret is repaired someone should run back and activate the first 3 and standby for the last one. When the final turret is ready, have the person call it out to the raid but be sure to finish off any Sentinels still standing and as many Watchers as you can, then have all dps move towards the center of the circle and click the final turret.
This brings Razorscale to the ground and all dps must immediately focus fire her as hard as they can, using cooldowns if possible and ignoring any adds still up. There is no need to tank her for this part and dps can and should go all out immediately with their attacks. You only have a short time before she break loose of her bounds and will then use Flame Breath to destroy the turrets, cast Wing Buffet to knock everyone away and take off back to the sky. Rinse and repeat this procedure until she is brought to 50% health.
Tanks and healers should feel free to contribute to the dps during these short ground phases as well.
Ground Phase:
Once Razorscale is brought to 50% health she will stay on the ground for the remainder of the encounter. A tank should immediately grab her and face her away from the raid as her Flame Breath attack can quickly kill many people. When this phase begins she will stop casting Fireballs but she does still use Devouring Flame, because of this the tank will need to slowly kite her around the circle while the raid groups up behind her and follows.
She will constantly apply a flame debuff to the entire raid throughout this phase and it should be dispelled from the tanks once in awhile to keep the breath attack from killing them. Razorscale also begins to apply a Fuse Armor debuff on the current tank that will slow their walking speed and lower their armor. Because of this tanks will need to switch off about every 2 buffs, otherwise they will take tremendous melee damage and will move too slowly to get out of Devouring Flames left on the ground.
Continue to kite, switch off tanking and keep dpsing until Razorscale is defeated.
Hard Mode:
NoneAchievements:
A Quick Shave - Defeat Razorscale without allowing her to fly into the air more than once.
Iron Dwarf, Medium Rare - Defeat 50 (25) Dark Rune Guardian Dwarves with Razorscale's Flame Breath. (This achievement is cumulative)
Video:
Tankspot VideoXT-002 Deconstructor
"Mimiron engineered this clockwork giant, who dominates the scrapyard area in Ulduar. XT-002 considers himself to be his inventor's son, causing the machine to behave like a young boy."
Decon is the next boss after Flame Leviathan that has to be killed in order to enter Ulduar itself. While Razorscale and Ignis are optional, Decon must be destroyed in order to gain access to the teleporter that brings the raid to the Antechamber. Decon was created by Mimiron and acts as the guard to inner Ulduar. The creation has the mind and voice of a small boy and treats the raid like toys to play with.
In 25man Decon has 22.5m hp and 5m hp on 10man. The fight is basically identical in both versions and like Patchwerk from Naxx, he serves as a gear check to the raid before allowing access to the rest of Ulduar.
Abilities:
Gravity Bomb - Charges the target with dark energy, causing them to explode and pull in nearby allies after 9 sec. After 9secs a gravity well will drop under the player and pull in all raid members within 10yds (20yds) and deals ~15k (12k) damage. (Move far away from the raid when hit with this)
Light Bomb - Charges the target with divine energy, causing them to sear nearby allies for 9 sec. Deals 3500 (2700) damage to all allies within 5yds, as well as the person debuffed with Light Bomb. (Stand at least 5 yards apart at all times and only melee will need to move, healers keep the person afflicted alive)
Tympanic Tantrum - Deals 10% damage every 1sec for 8secs. Nearby enemies are also dazed for the duration. (Everyone must help heal through this)
Soft Enrage: None
Hard Enrage: After 7min XT-002 Deconstructor will Enrage, attacking 150% faster and dealing 900% increased damage.
Adds:
XM-024 Pummeller - The largest add and easily distinguishable. These deal light melee damage and should be OT'd for the entire fight; do not dps.
XE-321 Boombot - These adds look like walking bombs and make a bee-line towards Decon. Ranged dps should nuke these down. They have low health and explode upon death or when they reach Decon, dealing ~16k Fire damage to anyone within 20yds (including other bots).
XS-013 Scrapbot - These adds look like little robot toys that also make a bee-line for Decon. When they get in range they will be absorbed by the boss and heal him for roughly 60k/bot. Scrapbots must be AoE'd down before reaching Decon and are the highest dps priority when they get close to the boss.
Strategy:
This fight consists of two basic phases that switch back and forth, other than that it's a fairly basic tank 'n spank encounter. The MT should run in first, waiting for Decon to be near one side of the room and then position him close to the wall between two junk piles.
Most of the fight consists of the normal attack phase at the start. During this phase the MT will hold Decon while dps keep burning him down. During this phase Decon only has 3 abilities that he uses: Gravity Bomb, Light Bomb and Tympanic Tantrum. The ranged classes should spread out roughly 6yds apart but make certain they are not spread out so far that healers are unable to reach them. If the ranged classes stand a short distance apart they should never need to move when Light Bombed. The melee should group up on Decon's back-right side. If a melee is hit with Light Bomb they can simply slide to the back-left corner of Decon's hit box and they should be far enough away from the other melee and the tank while still being able to dps. Whenever someone is hit with Gravity Bomb however, they need to move immediately away from other players. Ranged should find an open spot at least 10+ yards away (20+ yards in 10man) and melee should run to the back-right corner of the stairs by the boss, far enough away from the tank and other melee to not pull them into a gravity well.
The rough part of this fight is Tympanic Tantrum. This attack is channeled and does 80% of people's health over 8 seconds. Raid heals during this attack will need to be constant. The daze part of the attack will slow your movement speed to 40% which can make it difficult getting back into range of healers if you had to move recently due to Gravity Bomb; health stones for those situations are a good idea. Gravity Bombs and Light Bombs are no longer cast during a tantrum period, but they can still be active when a tantrum starts, so be aware of that.
The second phase of the fight happens 3 different times and is considered the Heart Phase or the Add Phase. When Decon reaches 75%, 50% and 25% health he will shut down momentarily and expose his heart. During this time he also has sparks flying out into the 4 corners of the room where the junk piles are, which brings to life the 3 different types of adds. The adds take awhile to become active and during this time all dps should focus fire Decon's exposed heart. The heart has roughly 10m hp in 25man and 1.5m hp in 10man. While exposed the heart will take double damage, and this damage will be passed onto Decon at the end of the heart phase. One word of caution however: do NOT kill the heart or you will activate hard mode for this encounter.
During this phase 1-2 OTs should run around the room and pick up any of the Pummeler adds that spawn and hold them for the rest of the fight. DPS should focus on the heart as much as possible, but also be sure to break off and kill any Boombots or Scrapbots that are closing in on Decon. If possible, ranged dps should try and kill Boombots that are walking through groups of Scrapbots as well since they will end up taking out the other bots when they die and explode.
Rinse and repeat until Decon is destroyed. Always keep an eye on Light Bomb and Gravity Bomb debuffs, help keep everyone alive during Tympanic Tantrum, and be sure to burn down any loose Scrapbots or Boombots that you see.
Hard Mode:
Decon's Hard Mode can be activated during any of the add phases when his heart is exposed. By killing the heart, you activate hard mode and Decon will heal back to 100% health. Keep in mind that this does NOT reset the enrage timer, which makes this fight basically impossible unless you kill the heart during the first add phase at 75% health.
In addition to restoring his health to 100%, Decon's battle limitations are lifted without his heart. This increases his total health by 150% and his damage by 40%. Hard Mode also introduces two more modifications to his usual arsenal:
Void Zone - Gravity Bombs summon a Void Zone that deals 7500 (5000) Shadow damage to enemies that stand within it.
Life Spark - Light Bombs summon a Life Spark that deals damage to nearby enemies. The Sparks have Static Charge, which deals 2000 (800) Nature damage to all enemies within 500 yards every 3 sec.
Achievements:
Nerf Engineering - Defeat XT-002 Deconstructor without him recovering any health from XS-013 Scrapbots.
Nerf Scrapbots - Defeat 20 XS-013 Scrapbots within 12 seconds using XE-321 Boombots.
Nerf Gravity Bombs - Defeat XT-002 Deconstructor without any raid member dying from a Gravity Bomb.
Must Deconstructor Faster - Defeat XT-002 Deconstructor in 205 seconds.
Heartbreaker - Defeat XT-002 Deconstructor after destroying his heart.
Video:
Tankspot VideoTankspot Hard Mode Guide