ODS (or Odies or Omnotron (Defense System) or Omnomnomotron) is the other initial encounter in BWD, and the one that's significantly more complicated for tanks.
There are four individual "bosses" in this encounter, any two of which can be active at the same time. On their own, not one is really anything special. The difficulty in this fight lies in dealing with them in constantly rotating pairs. The order is random each time you try the encounter, though the activations always go in sets of four. (i.e. None of the units will activate a second time before they've all been activated once. None of them will activate a third time before they've all been activated twice. etc.)
Each defense unit has a resource (energy) bar that starts at 100 and slowly drains (I think it takes about a minute). When the unit reaches 55 energy, a new one will become active. At 50 energy the unit will put up a shield (specific to each one). The shield lasts for 10 seconds, during which time you'll want to stop attacking. (This is a good time to pop Barkskin since you won't be getting the benefit of Savage Defense.) At 0 energy the unit shuts down.
At the start of the fight, there will be one active defense unit. Whichever tank is the initial tank will pick it up. Thirty seconds later, a new unit will activate. The second tank will have to pick up this unit. Another 30 seconds later, another new unit will activate and the first one will deactivate. The tank on the first unit will have to pick up the new one. This continues in a round-robin fashion until the encounter is over. (The units all share a single health pool.)
The first time each unit activates, it has a clean aggro table, so the first thing it's going to do is go straight for your healers. Be ready with your Growl and F3 to grab it if it's your turn. From that point on, each unit retains its aggro table when it shuts down, so next time it reactivates it will go back to the tank that had it last time.
When tanking one unit that's about to shut down, it's tempting to go stand near the next one that's going to become active. (You can tell which one because there will be an energy "stream" from the central tiki console thing to that unit.) Don't do this. There's a 2 or 3 second window between the time one becomes active and the previous one completely shuts down, which means you can get pummeled by both of them. Your healers won't appreciate this. Just be ready, pick them up from a distance, and let them come to you.
Each of the defense units has two abilities and a shield that you have to be aware of.
Arcanotron is the most demanding of the four units to tank. His first main ability is Power Generator. It puts a small, arcane-colored (blue/pink) void zone on the ground beneath his feet. He must be moved out of this immediately, as it increases the damage done by 50% to anyone (friend or foe) standing in it. Make sure to watch his buffs, as his hitbox is bigger than it appears. It can look like you've kited him away from it when you really haven't.
His other main ability is Arcane Annihilator, which is a 1.5-second cast Arcane blast. You're going to be taking turns with one of your DPS interrupting it. (You are specced 2/2 in Brutal Impact, right? You'd better be.) He casts about every 6 seconds, so you will need to share the duty and make sure you take turns.
Arcanotron's shield is Power Conversion. Be very aware of when it's going to go off. It's a 1.5 second cast, just like Arcane Annihilator. It's very easy to accidentally blow your Skull Bash on the shield cast, effectively wasting it.
While the shield is up every damaging attack will give Arcanotron a stack of Converted Power. It can be purged or spell stolen so a couple hits aren't bad (and can even be good if you have a mage with you), but you still don't want the stacks going up too high too fast. The trick here is that you'll still have to interrupt him while his shield is up. Get friendly with your escape key or use a macro like this:
/cast Skull Bash(Bear)
Electron, on the other hand, is the least demanding in regards to tanking. He has a chain lightning that you can't do anything about and a electric AoE damage debuff that he'll inflict on random raid members. You also can't do anything about this. So just hold him steady and tank away.
While his shield is up, any attacks against him will trigger damage on a random raid member and anyone standing near them.
Magmatron isn't much harder to tank than Electron, but requires a little more awareness.
His first major ability is a channeled AoE fire blast that just has to be healed through.
The other is a two-stage ability where he'll first focus on a target and then do a heavy-damage channeled fire cone in their direction, extending all the way to the end of the room. This can't be avoided. He'll turn to always face the target.
Ideally you'll want to hold Magmatron near a wall, facing parallel while tanking him. This way the targeted person can just go stand against the wall and everything will be fine. If you are tanking Magmatron, this won't target you.
As a tank this becomes a dangerous ability when you're tanking an active unit other than Magmatron. If he targets someone standing between himself and you, you'll be in the blast path. If you see this happening, move quickly. There's also a possibility he'll target you, at which point you should be hitting Survival Instincts.
Magmatron's shield absorbs all damage done to him, up to a certain amount. If it reaches that point it bursts, doing 75K fire damage to everyone in the raid. Ugly.
Toxitron is somewhere in the mid-range for tanking difficulty. He's harder than Electron and Magmatron, but easier than Arcanotron.
His first ability is Chemical Bomb, which creates a large cloud at the feet of a random raid member, including the Toxitron tank. Anyone standing in the cloud, friend or foe, takes an additional 50% damage. As long as you can do it without holding Toxitron right in the middle of the room, you'll want to position him so that he is in the cloud and you are not. Anyone in the cloud turns a green color, so it's easy to tell.
Twice while he's active, he'll also do Poison Protocol, which summons 3 slime adds at his feet, 1.5 seconds apart. Each separate slime will fixate on a raid member and start chasing them. If the slime reaches its target before it dies it will explode, doing massive AoE damage near it and leaving a slime puddle on the ground.
These are the reason I mentioned not holding Toxitron in the middle of the room. It gives the rest of your raid a definitive direction the slimes will be coming from and an easier space to use to avoid/kite them.
The slimes can be slowed. I'm not sure about rooted or stunned.
The adds will not fixate on the Toxitron tank, but they can fixate on the non-Toxitron tank. If you're not tanking Toxitron, be alert. You may have to kite the boss until DPS takes care of the one after you.
Stampeding Roar can be helpful here if you see one of the slimes getting close to you or close to a target standing near you.
Also, you'll be able to use Berserk during one of the two add "phases". (I usually choose the 2nd since the rest of the raid is focused on a different defense unit by then.) Spamming Mangle on Toxitron as the adds spawn will put out some good initial damage. It will also put an initial slow on the adds if you've specced into Infected Wounds.
Once your raid defeats the encounter, you'll be looking for the Lightning Conductor Band and the Poison Protocol Pauldrons.
As with all my boss strats, I'm writing from the overall perspective of a Bear tank (in 10-man) and what they will need to do. For you Cats reading this blog, I suggest you check out Dinaer's guides on Forever a Noob. They're written for Rogues but are a pretty good guide for melee in general and his gear drop suggestions (with the exception of weapons) will be spot on for Cats. If I have additional insight, I will try to add it in my blog.
Horridon the horrible
12 hours ago