The trash guarding the Plagueworks has stepped it up a notch from their brethren downstairs. Your first opponent will be a simple Val'kyr warrior, with one special ability: summoning clones of your raid mates. She'll make a couple of clones that will begin attacking / healing and causing problems for your group. If one of these copies is a healer, swap to that target and lock it down. The heals are potent and can cause problems killing the Val'kyr if you're not careful. Once the Val'kyr is down, clean up the adds and move on.
The next few trash packs are going to be pretty simple, let the tank get aggro (and help out via Tricks of the Trade), and then go to town with Fan of Knives. You'll fight some familiar trash mobs from Naxxramas, and eventually come up against Stinky and Precious. These are the Gluth-like protectors of Festergut and Rotface, respectively. You'll want to focus on whichever dog you want to fight first, and make sure to tank them in a safe area. While fighting Stinky, you'll be taking constant AoE damage. Use Feint to negate some of the damage, and focus on nuking the boss. While fighting Precious, he will summon a pack of adds to cause problems for your raid. Save Tricks of the Trade to send these to a tank or other designated kiter.
The first true boss of the Plagueworks, Festergut is quite possibly the most rogue-friendly fight in the game (this was the fight that was seen in last week's raid damage analysis). A true tank-and-spank with a hard enrage timer and nothing to do besides unload damage. You'll be tasked with standing behind Festergut for the entire fight, and making sure he goes down before the enrage timer goes off and he wipes the raid with a powerful belch of poisonous gas.
While there are several mechanics on this fight to worry about, the only one that concerns rogues involves a Spore debuff that will be placed on a few raid members. Think of these like the beneficial spores on Loatheb: everyone wants to be in range when it pops. As a melee, you're usually tasked with standing still, and someone else (or another melee) will bring the spore to you. If you happen to have to run a Spore to the ranged group at your leader's request, use Sprint, as that's the only time you'll need it. Otherwise, enjoy a long DPS burn with nothing else to worry about. Don't bother using Feint to reduce any of the AoE damage you're taking: every little bit of DPS is crucial to downing Festergut before his pretty tightly-tuned fight timers. Try to trade Tricks with another rogue, or use it to boost your raid's DPS even higher. Use this as an opportunity to show your raid what you can really do when you have the perfect 'rogue encounter'!
Of course, the next boss encounter would be a melee-unfriendly fight. Rotface plays like Grobbulus meets Razorgore (not Razorscale). There's two key stages in this circular room: the boss area, and the add kiting area. You'll want to maximize your time in the boss area, and minimize your time in the add area. Movement and reaction times are 90% of this fight, and keeping a cool head and zooming your camera out quite a bit will make all the difference in the world. One note on this fight: you'll want to use Bloodlust early due to the boss' pacing mechanics later in the fight, so pop all your cooldowns as soon as Bloodlust is called for.
The basic premise of the fight is that you're fighting Grobbulus 2.0, with a few changes. The boss is still an ugly plague creation, and he will still spray some nasty poison in a cone in front of him. The difference is that now he will randomly turn to face a raider, and spray in their direction, then return to face the tank. You must always be cautious to be behind the boss, and you have to run out of his frontal cone when he turns to spit. If not, you'll take some pretty hefty damage, which you can Feint if you absolutely can't get away.
The second change is that Rotface doesn't drop any slime or clouds of his own: Professor Putricide instead releases slime into the room on one of the four sides, which slows your movement and deals pretty heavy damage. As long as you remain near the boss, the slime on the room's exterior shouldn't bother you at all. Your off tank may be running through the goop, and so if you have to reach him, use Sprint and Cloak of Shadows to minimize your incoming damage. Why would you run to the tank in the slime? Good question!
The final change is the mechanic behind the slimes that Rotface spawns. Unlike Grobbulus' slimes which can be killed, these slimes must be kited by an off tank. They'll be kiting the slime around the room, making sure to stay clear of any raid members. The slime that is being kited will deal massive damage to anyone in melee range, regardless of threat, so avoid being anywhere near it at all costs. Rotface will begin marking raid members with an infection, which causes them to spawn a slime (instead of dropping a cloud). The trick is to merge all of the slimes together into a massive slime, like making a giant snowball. Once enough slimes are rolled together, the slime explodes, and shoots a Shadow Crash-like attack at all raid members. Find an empty spot on the floor (no slime or players there), and run to that spot when the slime explodes.
If you're infected, you will soon spawn a small slime. It's your duty to run to your off tank, standing in FRONT of the big slime being kited, and letting your small slime merge into the bigger slime. Your slime will leave you once you are near the big slime, so you can run back to the boss as soon as it leaves your side. It will take a few tries for you to get used to this mechanic, so observe what happens so you can refine your technique. Minimizing your downtime between running to the off tank and getting back to the boss, while avoiding the Slime Spray, will give you quite the challenge. Focus on maximizing your uptime on the boss, by using any speed boosts you have to reach the off tank faster, watching where the off tank is at all times so you know where to run, and even burning all of your energy before leaving the boss' side.
The father of the twin abominations you just crushed, the Professor is definitely the most potent boss you'll face in ICC up to this point. He's a 3 phase encounter, with phases 1 and 2 being pretty similar, and phase 3 switching to a pure DPS burn. The keys to succeeding are quick reaction times and target swaps to the spawning slime / gas adds, and avoiding the myriad of attacks the Professor will use against you. You only have 10 attempts per week to attempt the Professor (15 with this week's release of the Blood Wing), and so keen awareness and avoiding stupid deaths to avoidable damage become paramount.
In phases 1 and 2, the boss will be spawning slimes (green) and gas clouds (orange), alternating between each. The raid will be focusing on killing these adds first and foremost, and so consult your raid leader with how they'd like to have melee handling the adds. Typically, I have the melee (including rogues) attack the green slimes once they're within 15 yards of the targeted player, and I have the rogues stay on the boss for the orange slimes as the ranged classes work it down.
The green slimes explode when they reach their destination (they tunnel vision one player and go straight to them), and the resulting explosion has a meteor-like damage distribution: it is shared evenly between all players in range. It's very important that you eat this explosion, and use Feint to absorb as much of it as possible. Follow the green slime to the intended target, and stand there as the explosion happens. Once it picks a new target, feel free to re-engage and destroy it.
If you're targeted by the orange gas cloud, you need to run away from it ASAP. Try to stay in range of your healers, as you'll be taking some serious damage from the gas cloud's channeled attack. Use Sprint to avoid it, and let your casters do the rest of the work for you. Get back onto Putricide as quickly as possible: pushing him past the add-spawning phase is key, and melee DPS will be doing the majority of the damage to the boss.
During phase 2, Putricide will assault you with a variety of attacks. He'll drop slime pools (he drops these in P1 too), and you need to stay away from them, or risk a 4,000 damage per second debuff. He'll also drop Choking Gas bombs, which lower your chance to hit by 75% for a time, and deal massive damage when they explode. These look like orange, gas-shrouded lanterns on the floor. He also throws a Malleable Goo at any targets at range, so make sure you're up close and personal with the boss to avoid being a target for one of these deadly attacks. Proper position will take some time to learn, but try to stay behind the boss while minimizing slime / gas damage and avoiding the gooey ooze he throws around.
Phase 3 introduces a far stronger Putricide, who begins flooding the room with slime. Eventually, this abundance of slime will fill the room, and cause your raid to wipe. If you took too long to get him to phase 3, which is the "burn" phase with no adds (but still plenty of traps on the ground), he will enrage after a time. Finally, if you spend too long in phase 3, he'll start hitting the raid for such massive damage that you'll surely die (think of Hodir's Frozen Blows, except permanent and ever scaling upward). Three ways to die and only one way out: burn the boss so hard he dies before any of these enrage styles ends up on your Death Certificate.
The Plagueworks represents a new level of difficulty in raid fights, and most of the bosses here are unlikely to be defeated by any true PUG, especially on 25 man. Focus on finding a regular group or guild you can attend with, and enjoy the opportunity to both show off your chart-topping DPS and your reaction times and situational awareness abilities on very unfriendly fights. With the Blood Wing recently released, there are only 3 more encounters between us and Arthas. If you want to be a part of the assassination of the Lich King and the fulfillment of our original mission in Northrend, being honing your skills and preparing for the battles that lie ahead.