This Week in Raiding: Healing Omnotron Defense System

This Week in Raiding is a (hopefully) weekly feature discussing the raiding encounters that my guild tackled this week, the lessons learned from them, as well as any news or thoughts on raiding in general. This week we have the Omnotron Defense Council encounter from the perspective of the Holy Paladin, although much of this article will be useful to all healing classes.  This is not a strategy guide, but everything that you need to know to heal this encounter successfully.  If you would like a more detailed description of the fight and overall strategy, please check out Tankspot's write up and video.

The Omnotron Defense System is a group of four Golems that make up what is typically considered the second boss encounter in Blackwing Descent.  It is a Council style fight; the bosses share a health pool and have a lot of abilities, making this a complex and chaotic fight.  Environmental awareness from the raiders and clear communication from the raid leader are keys to downing this fight reliably.

My raiding team uses the following raid composition for this fight:  Two tanks, three healers and 5 DPS.  A typical raid composition for 25 man would be Two tanks, six healers and seventeen DPS.


Magmatron is the fire boss.  He has two abilities that are going to make a healers life difficult: Incineration Security Measure and Flamethrower.  
  • Incineration Security Measure is a raid-wide area-of-effect flame ability.  It has a very obvious flame graphic that is impossible to miss.  You can't avoid this damage, even thought the graphic makes it look like you can, so don't try.
  • Flamethrower is a single target ability that shoots a jet of flame, does a lot of damage and is preceded by Acquiring Target, which projects a very large and obvious red laser beam at it's target for four seconds.  The raid needs to run away from the path of the laser beam, and the person targeted needs to stand still so that they don't spread the damage to other people.  The healers should start precasting heals or use mitigation cooldowns on the target in order to ensure survival.  As a Paladin, if you Divine Shield yourself while the laser is targeting you it will cancel the effect entirely, and Magmatron will not cast his flamethrower.  Hand of Protection has no effect on this ability.
Toxitron is the poison boss.  His bag of tricks consists of Poison Cloud and Poison Protocol.
  • Poison Cloud. Toxitron will periodically spew poison clouds at a random target that gives whoever stands in them a 50% increased damage debuff.  This includes the boss, so it's likely that your tank will try to stand the boss in the cloud, so be ready to heal through the extra damage if your tank isn't positioned perfectly.
  • Poison Protocol is the ability that caused my raid group the most difficulty.  The boss will release 3 poison slimes that will randomly target a player and move towards them.  If they reach their target, they explode and create a large poison puddle.  Getting hit by a slime is instant death.  They are untauntable and need to be burned down by the DPS as quickly as possible.  Avoid them at all costs (See below).
Electron is the lightning boss.  He does Electrical Discharge and Lightning Conductor.
  • Electrical Discharge is a fairly straight-forward chain lightning ability.  Spread out a minimum of 8 yards and be mindful of other people moving close to you.  It is not hugely damaging unless it's being spread to a lot of people.
  • Lightning Conductor is placed on a random raid member and will do electrical damage to that person and anyone around it.  If it is placed on you, run out of the raid.  As well, be aware of other people around you who have it and stay away from them, especially if it happens to be on the tank.
Arcanotron is the magic boss and he is responsible for Power Generator and Arcane Annihilator
  • Arcane Annihilator is a large damage, single target ability that will be the responsibility of your tanks and melee damage dealers to interrupt.  As a healer, be aware of sudden health dips when Arcanotron is up.
  • Power Generator is a hugely important mechanic for all casters, including the healers.  Arcanotron will put a puddle underneath his feet which will increase his damage significantly.  It's the tanks job to move him out of this.  The ranged DPS and the healers should stand in it for a damage boost and mana regeneration (See below).
Shields:  Two bosses will be active at any given time (except the very beginning), one active and one protected by a shield.  It's vitally important not to attack the boss with the shield active.  Each shield has a powerful effect that will go off if it is damaged, so target switching is extremely important.  Even a stray Judgement can cause a ridiculous amount of damage to the raid.

The only exception is Toxitron's Poison Soaked Shell, which will put a stacking damage-over-time debuff on anyone who attacks it, but also gives a large burst damage increase.  This debuff can be Cleansed, but many raiders will pick up a couple of stacks intentionally for the extra damage.  Ask beforehand if your raid leader wants it cleansed, but in my experience, just leave it if the person who has it is in no danger of dying.  Watch their health closely though, in case they get a bit overzealous in grabbing stacks.


As always, Judge as often as you can for the mana regeneration.

If you are using your Focus Target to determine your Judgement targets, it's important to put it on the right person in this fight.  It is not optimal to Focus/Judge on a tank on this fight because 50% of the time the tank is going to be targeting a boss with his Shield up.  It's better to Focus on a Ranged DPS who is reliable at switching targets, and it's even better to focus on the Raid Leader who is calling out the switches, if possible.

Judging the wrong target on this fight could potentially cause a lot of damage to your raid.  Be careful of your targets!

(or Using Power Generator for Fun and Profit!)

Arcanotron will create a blue puddle on the ground which will give him or whoever is standing in it a damage buff.  Your tank will move him out of this puddle.  You need to stand in this puddle as much as you can, as it regenerates mana while you stand in it.   

Power Generator also grants a damage buff as well, so your caster DPS is going to want to jump in the puddle with you, which most of the time is fine.  It gets problematic when Arcanotron and Electron are up at the same time, however, the chain lightning will cause an insane amount of damage if half the raid is stacked up, costing more mana to heal than will be gained from the puddle.

It's best to keep the DPS out of the Power Generator in this case, and let the healers regenerate their mana.  The damage caused by Electrical Discharge chaining to the 2 or 3 healers (5 or 6 in 25man) is very easy to heal through.  Talk to your raid leader about this if it becomes a problem.


There is no excellent and obvious period of low damage in this fight to regenerate mana using Divine Plea, so I recommend using Guardian of the Ancient Kings to offset the 50% healing reduction.  Since GAK has a 5 minute cooldown, you can only do this combination once during the fight.  If you are having major mana problems, use Avenging Wrath and Divine Favor in combination with Divine Plea throughout the fight.

If I am on the ball and using the Power Generator wisely, I find that I only need to use Divine Plea once during this fight, so GAK is a perfect offsetting cooldown.  Use your discretion based on your own mana needs.

If you have any Spirit trinkets - like Core of Ripeness - use those on cooldown.


In the 10-man version of this fight, your raid is going to be spread out a lot making it difficult to hit the 5 (or 6, glyphed) people needed to really make Light of Dawn worth it, so Word of Glory is a stronger choice most of the time.  With the increased amount of people in a 25 person raid, Light of Dawn would be the go-to Holy Power heal much of the time.  Just be mindful of how many people you will hit with your LoD before you cast it; if it looks like you won't hit 5 people (pets count too, remember), then go with WoG.

When everyone stacks in the Power Generator, Light of Dawn will be much easier to use effectively in 10-man.


For a healer, range awareness is key to this fight, as everyone will be moving around a lot and can easily get out of range at a crucial time, causing a death. Stay in the middle of the room as much as you can, and be prepared to move to either side as the situation warrants. Keep an eye on your tanks and make sure that you keep them in range.


One of the tanks will get the Beacon of Light. There will be only one boss when the encounter begins, so put your Beacon on that tank.

If you are finding that one of the tanks is out of range a lot, put the Beacon on him instead. Beacon of Light has a 60 yard range, far greater than any of a Paladin's heals. This way you can ensure that if a tank is out of range he is still going to be receiving some healing while you reposition yourself to get within range again.

Unless your raid has incredibly high DPS, this fight will last longer than the five-minute duration of your Beacon, so be prepared to reapply it as needed.


Probably the single most frequent cause of wipes on this encounter will be Poison Protocol.  It sounds simple in theory:  Avoid the Slimes.  It's a bit harder in practice, however.
  • First thing to do is position yourself as far away from Toxitron as you can while he's active.  Space can get a little tight when both Toxitron and Electron are up, but I'd rather let an Electrical Discharge chain once or twice than be too close to the Slimes when they spawn.
  • Set up your Raid Frames to show Aggro.  I have a big, menacing looking red box around my frames to indicate aggro that is hard to miss.  Hopefully your Raid Leader will call out the Slime targets as well.  Either way, once you realize you are targeted by a Slime, start running away from it.  The Slime will only explode if it hits it's target, so it's absolutely vital that it doesn't get to you.  Healing does not matter as much at this point.
  • Run around the outside of the room to give your DPS the most time to burn down the Slimes.
  • Use the Speed of Light speed bonus from Holy Radiance to put some distance between you and your Slime.  This will also spread some heals around the room as you run.
  • Do not let it get too close to you.  It has a much larger range than it would seem.


Try to have Resistance Aura up so that can use Aura Mastery during Magmatron's Incineration Security Measure AOE. If you can time it correctly, you can have double resistance for the entire time this ability is active, substantially reducing damage.

Devotion Aura is much less useful for a Holy Paladin in this fight, as the incoming physical damage is very light. Let another Paladin or a Shaman put that buff on the raid.

Save using your first cooldown until the second boss activates. Aside from Magmatron, the damage caused by a single boss is very minor - Toxitron especially. Divine Favor and Avenging Wrath should be used as often as you can, unless you are saving them to offset Divine Plea (see above). I prefer to save them and hit them just after a boss switch. Magmatron is the big AOE damage dealer in this fight, so if you are assigned to healing the raid, save your cooldowns for when he's active.

Hand of Sacrifice is best used on the target of Flamethrower, or on a tank that is taking extra damage from standing in a Poison Cloud.

Save Divine Shield for Flamethrower. If you are targeted by Acquiring Target, hit your bubble and the flamethrower will not go off at all. If Divine Shield is on cooldown, use Divine Protection to help mitigate some of the damage.

Guardian of the Ancient Kings should be saved to offset the Divine Plea debuff (see above).


Omnotron Defense Council drop two items that are good for Holy Paladins: Security Measure Alpha and Life Force Chargers. Both are worth getting.

* Big thanks Ophelie and Leetsauced for answering a few questions on Omnotron 25, and Rades for helping me get the Wowhead hoverlinks working.  Thanks, everyone!

1 comment:

  1. Good writeup. The first few times that I went here, I was completely baffled by all the stuff going on. It's one of those fights that the more you do it, the easier it gets.