Gaseous Blight

This is basically a tank and spank fight with a few group up and spread out scenarios. It has a 5 min enrage, and basically serves as a gear/dps check for the raid.

First thing of note, the room will be covered with an orangy gas, the Gaseous Blight. It's a constant damage aura for the raid to heal through.

Inhale Blight

Festergut will start inhaling the Blight every so often. Each time he does, the aura damage goes down, but he increases his own damage done by 30%. So, less raid damage, more tank damage, be aware to shift focus.

Pungent Blight

After 3 inhales, the room is cleared of the aura and his damage is up by 90%. After 20 sec or so, he will perform this, expelling all the gas back into the room, resetting his own debuff (back to normal damage), and dealing about 50K damage to the entire raid.

Instant death to most unless...

Gas Spores

Every so often he'll throw out 3 Gas Spores (2 in 10 man) into the raid. The look like Loatheb's spores, but they're on a player's head. People need to group up with them, let the timer on it run down so it explodes all over them. But try not to have more than 1 spore in the same area due to...

Blighted Spores

This is a 6 second 2K ish DoT that the Spores leave on you after they explode, and it stacks. Heal through this raid damage, it is neccessary because...

Innoculated

This is a debuff you get should you survive the Blighted Spores. It gives you a 25% shadow damage taken reduction, and it stacks. This is what the raid needs to survive the Pungent Blight. There will be 3 opportunities to get it, and you'll likely need at least 2 in normal modes, all 3 in hard modes.

Gastric Bloat

Last couple of tricks this guy does are... Gastric Bloat is a stacking debuff on the tank. It makes him do 10% more damage per stack, and to reiterate, that's more damage he does, not taken. But at 10 stacks, he dies in a horrific explosion likely taking some melee with him.

So this forces it to be a 2 tank fight, tank swaps at 8-9 stacks, then help dps without pulling aggro back.

Vile Gas

This is for the ranged to deal with. With sufficient numbers, this targets the ranged, disorients them and makes them puke (damage) all over anyone around them. So this is the spread out mechanic. This will not occur during Gas Spores, so the raid works to group up and spread out whenever it calls for it.

Heroic Mode Summary

There's one new trick and that's Malleable Goo. Professor Putricide joins the fight and starts throwing them from the balcony. There'll be a small green goo puddle where it's gonna land, through the explosion radius is far larger. They hurt, give a debuff that increases your casting and attack speeds. Best to avoid them.

This forces the raid to be more out, like if you had healers stack on melee before, might be best to leave them out. More targets for Malleable Goo to target instead of it constantly doing melee. For the melee though, probably want 2 areas to run to, likely on either side. Don't be on the side the Goo lands at.