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Siege Vehicles Basics

Before the fight even begins players will be split up into different siege vehicles. You will use these vehicles to defeat the dwarven army ahead of you and ultimately, Flame Leviathan. On heroic mode there are 4 of each vehicles and on normal mode there are 2 of each vehicles.

Siege Engine Driver - Attack buildings by ramming them, knock back mobs, and engage a speed boost
Siege Engine Passenger & Gunner - Shoots pyrite ammo out of the air, helps shoot targets on the ground
Demolisher Driver - Shoots fireballs and pyrite barrels
Demolisher Passenger & Gunner - Picks up pyrite ammo to reload the demolisher, may also load launch the passenger from the cannon
Chopper Driver - Drops inflammable oil slicks, may also pick up players to protect them from damage and death
All vehicle passengers may pick up explosive to throw at the dwarven armies.

Siege Vehicle Abilities

Salvaged Siege Engine

Health Points:
Driver x 1, Gunner x 1, Passengers x 2
Driver Abilities:
Ram (40 energy) - 5400-6600 damage with a knockback addition
Electroshock (38 energy) - Spell interrupt with a 4 second lockout period, 25 yard cone effect
Steam Rush (40 energy) - Charges very fast with a minor damage on impact
Gunners Abilities:
Anti-Air Rocket (10 energy) - Rapid fire long range (1000 yard) missile launcher
Cannon (20 energy) - Launches a cannon ball that does medium damage
Salvaged Demolisher

Health Points: 428,000
Driver x 1, Passengers x 2
Driver Abilities:
Hurl Boulder - 13,500-16,500 damage, ignites oil slicks dropped by choppers.
Hurl Pyrite Barrel - 27,000-30,000 damage, consumes 5 pyrite
Ram - 8550-9450 damage with a knockback addition
Throw Passenger - Launch a passenger who has loaded themselves into the catapult.
Passenger Abilities:
Cannon - Fire a cannon ball forward, explodes after traveling 50 yards dealing damage in a 10 yard area of effect radius.
Grab Crate - Pick up a crate with your hook, reloading the demolisher with liquid pyrite.
Increase Speed - Uses the liquid pyrite you’ve been picking up, increases movement speed by 100% for a 1 minute duration.
Load into Catapult - You get in the catapult and the drive may fire you as a projectile.
Salvaged Chopper

Health Points:
Driver x 1, Passenger x 1
Driver Abilities:
Sonic Horn (20 energy) - 3150-3850 damage in a 35 yard range frontal cone.
Tar - Lays down a pool of tar that slows enemies by 75% for a 45 second duration. This pool may be ignited by demolishers.
Speed Boost (50 energy) - increases the vehicle’s movement speed by 100% for 5 seconds.
Dwarf Army Mobs

Steelforge Defender:

Health Points: 8,316
Titanium Stormlord:

Health Points: 75,600
Melee hits are around 1,500 damage
Cyclone - Hits demolisher vehicles for approximately 3,000 nature damage
Ulduar Colossus:

Health Points: 315,000
Shockwave - casted ability, should be interrupted by siege engines
Buildings and Towers

Note that in order to complete this encounter on hard mode for achievements and additional loot you must leave up at least one tower. The more towers you leave up better quailty and increased amount of loot you’ll receive.

Tower of Nature (Freya’s Ward) - Deals 15,000 nature damage and summons guardians of nature
Tower of Frost (Hodir’s Fury) - Deals 15,000 frost damage, attacks entomb enemies in blocks of ice
Tower of Flames (Mimiron’s Inferno) - Deals 15,000 fire damage, leaving a fires behind
Tower of Storms (Thorim’s Hammer) - Deals 15,000 damage
Storm Beacon - Each beacon summons ads in a small radius.
Flame Leviathan Abilities

Flame Jets - Channeled cast, deals large radius area of effect damage, 2000 damage per second, cast lasts 10 seconds.
Battering Ram - Knock back on target that’s within melee range. Applies a debuff to the knock backed target increased damage taken by 100%.
Gathering Speed - Increases movement speed, 5% per stack up to 20 stacks.
Missile Barrage - All players and vehicles take 700 damage every few seconds.
Hard Mode Strategy

Raid groups attempting to defeat Flame Leviathan on hard mode will need to leave at least one tower up. These towers place a pillar of light on the ground (associated colors below) that deal their respective abilities. Note that these beams can be avoided.

Storm Tower (purple) - lightning balls come down from the sky
Flames Tower (red) - beam moves across the ground leaving fires behind
Frost Towers (blue) - freezes players and siege engines
Nature (green) - spawns adds that must be killed
Flame Leviathan Boss Strategy

As soon as you engage Flame Leviathan he will randomly target a siege engine vehicle. The driver of this vehicle must kite the boss. Initially it’s very easy to kite, but as time passes Flame Leviathan will begin to pickup speed, making it more difficult.

Every 30 seconds Flame Leviathan will target a new siege engine, which will be tasked with kiting (if a siege engine is not alive he will target a demolisher or chopper). This fight really comes down to the kite and each vehicle fulfilling its role successfully (as described below).

Siege Engine Role

While this kiting is going on other players in siege engines can be doing damage with ram and more importantly using electroshock to interrupt flame jets. However, be prepared to kite as the 30 second kite cycle comes to an end. The passengers of the siege engines should be shooting down pyrite ammo in the air. If there aren’t any pyrite ammo left they may DPS the boss.

Demolisher Role

Demolishers are the bulk of the damage output on this fight. Your demos should be attacking the boss with hurl boulder, hurl pyrite barrel, and launch passenger. In order to maximize damage it’s a good idea to save your hurl pyrite barrel for when the overload circuit has been activated.

Interlude on Catapult Passenger Launch

After your overload circuit wears off you’ll want to have your demolishers launch a single DPS class and a single healer to the back of Flame Leviathan. There are 4 turrets here, after killing a target a button will pop up. You will channel a cast on this button and upon completion Flame Leviathan will be stunned, increase the damage you deal to him by 50%, and reset his movement speed. These players will be knocked off Flame Leviathan and should be promptly picked up by a chopper and returned to a demolisher, in preparation for the upcoming launch.

Choppers Role

Chopper’s are tasked with dropping their flammable oil slicks on the ground in front on Flame Leviathan. This will slow him and deal additional damage if they catch fire. In addition, choppers should be picking up any players that are coming off the back of Flame Leviathan or players that have been launched and missed their targets.