WoW Ulduar Raid Boss Guide - The Iron Council (Assembly of Iron)
This guide to the 5th boss in the Ulduar raid instance in World of Warcraft focuses on the "normal" mode, where raids go in and kill Stormcaller Brundir, the smallest of the three bosses in the council, last. We take a look at boss abilities, positioning, and how to defeat this encounter.
You Will Not Defeat the Assembly of Iron So Easily!
OK - definitely not a true statement, but Steelbreaker seems convinced. In this not-all-that-difficult boss fight (technically the 5th in Ulduar, although it can be done third), you actually battle three different bosses at once, each with their own individual array of abilities specifically designed to smash your raid's face. Of course, taking all three head on is the quickest way to die - so you have to use some specific tactics in order to take these three guys down.
The Iron Council has three modes - Easy, Medium, and Hard. Most raid groups will start off with easy and progress through the possibilities. The mode is set depending on which boss you decide to kill last. The bosses come in 3 different sizes: An Iron Giant (Steelbreaker), an Iron Vrykul (Runemaster Molgeim), and an Iron Dwarf (Stormcaller Brundir). Easy mode involves killing them in largest to smallest order. Medium is killing the middle last, and hard is killing the largest last.
In this guide we're going to talk about the abilities of each boss, and how to execute the fight on normal mode.
When you engage the Assembly of Iron, the first thing you're going to want to do is position Stormcalled Brundir as far from your raid as possible. This is because he has an ability called Overload, which does massive amounts of damage in a 30 yard AoE. It can easily kill a lower health raid member. Steelbreaker is normally tanked near the entrance of the room, and Brundir and Molgeim in the back. On 10-man mode, one tank can handle both Molgeim and Brundir while another tanks Steelbreaker.
On 25-man mode, you'll typically assign a tank to each boss, allowing Molgeim to be tanked closer to Steelbreaker where he can drop buff runes (blue circles) for the raid to stand in to increase DPS. Note: Don't allow either Steelbreaker or Molgeim to stand in these blue circles - not moving Molgeim and Steelbreaker immediately out of the circle will most often result in a wipe because the tank will die almost instantly.
Taking Down Steelbreaker
For normal mode, we want to kill Steelbreaker first. He does a light AoE aura around him which will hit anyone in melee range, but it is easily healed through. Other than that, his damage is focused on the tank, and this damage is fairly considerable.
Rune Punch is the most important ability to have a solid understanding of. It has a cast time, during which Steelbreaker will hold his fist in the air and it will emit a big blue glow. After that he'll smash it onto the tank hitting him for a considerable amount - around 50% of his life, and inflicting a powerful dot. If allowed to tick once, it will often kill the tank. If it clicks twice, your tank is definitely dead. Because of this someone with a magic dispel, like a Priest or Paladin has to constantly be watching for the Rune Punch so they can cleanse it off of the tank before it ticks.
On 25-man, where Brundir will be casting blue circles under Steelbreaker, careful positioning will allow you to give the buff to melee as well as ranged. This is risky though, because you must be precise. You can't allow Steelbreaker to get the benefit of the blue rune circle even for a moment. With steady DPS and careful positioning, it doesn't take very long to bring down the large Steelbreaker.
Moving on the Runemaster Molgeim
When Steelbreaker dies, Molgeim and Stormcaller Brundir will gain new abilities. Firstly, the tank formerly on Steelbreaker needs to taunt Molgeim and move him to the other side of the room, where Steelbreaker was killed. This gives the raid plenty of room to focus on the Runemaster without having to worry about Brundir's Overload.
With Steelbreaker dead, Molgeim gains two new abilities. The first one of these is called Rune of Death - Molgeim will place a large, green, runic circle on the ground which will deal heavy constant damage to anyone who doesn't immediately move out of it. Because of this, it is important to have plenty of space for the raid to move. This circle is actually targeted on a player, so staying spread out can help minimize the damage. However, he will still be dropping blue buff runes on the ground which the raid will want to stack in. If players are going to stack in blue for the damage buff, they have to be prepared to run as soon as the Death Rune lands - because it will be directly on top of them. While repositioning Molgeim away from Death Runes, the tank needs to also ensure that he doesn't bring Molgeim too close to Brundir for fear of players getting hit by Overload.
Molgeim's second new ability is called Shield of Runes. This is basically a self-buff that increases Molgeim's damage by 50%. It's best for a Mage to spellsteal this buff, but a Priest or Shaman can dispel/purge it as well.
I Choose You, Stormcaller Brundir!
After Runemaster Molgeim has been killed, the raid can move in on Stormcaller Brundir. Keep in mind that, in addition to his new abilities, Brundir will still do Overload, so anyone in melee range needs to be prepared to run for their lives. Brundir's only other ability during the beginning of the encounter was Chain Lightning, which was fairly negligible since only one player - the Brundir tank - was ever in range of it. However, your raid may find it beneficial to use a Warrior to tank Brundir the whole time as they can interrupt Chain Lightening, making the healers' job easier. Not only that, but a Warrior tank can use Intervene to get out of range of the Overload quickly.
After Steelbreaker is killed, Brundir gains another ability called Lightening Whirl. This is a whirlwind-esque magic ability that can also be interrupted.
After both Steelbreaker and Runemaster Molgeim have been killed, Brundir gains his final ability: Lightening Tendrils. When Brundir uses this ability he will rise up into the air and emit AoE lightning tendrils to anyone he comes close to, which deal a significant amount of damage. He will choose a random raid member and follow them, so the key to surviving this ability is quickly identifying who is being chased and having them kite him away from everyone else. Note: He won't follow the same person the entire time - he will switch, often several times before returning to the ground.
The Bottom Line
This is definitely a fight that requires the entire raid to watch themselves constantly. There are lots of opportunities for players to get tunnel vision and very quickly get themselves killed. Hair trigger reaction times are a must for everyone. If your raid can pull that off, then it really is a simple fight. Above all, the key to killing defeating the Assembly of Iron is to avoid unnecessary damage from "bad stuff" (green runes, overload, tendrils), keeping the whole raid alive, and pushing DPS hard.