Vashnik the Malignant

Setup:

• The whole fight happens in one spot, between the fire and shadow fountains.
• Tank the boss next to the shadow fountain.
• The ramping damage is always on you; it's low enough to sustain.
• No DPS enrage, so a 5th healer is a safe choice.

Every cycle:

• Spread to soak every Catalytic Bile.
• Healers dispel the fire debuff one at a time, when the raid is stable.
• Dispel in the assigned order, one at a time, whenever the raid is stable.
• Kill the shadow adds (Shrouded Venom). Dodge the pools and the waves.
• Heal through Imbibe.

Fire adds (3 Burning Venom):

• Banish one and kill it last.
• Grip the other two to the middle, then grip one of those to the boss.
• Kill them one at a time, never together.

Malignant Totems (the real Mythic mechanic):

• They spawn at random across your half of the room and can't be attacked.
• The only way to remove one is to hit it with a Plague Froth wave. You get 2 sets of waves per cycle.
• Any totem alive when the next Imbibe goes off fires Malignance: a raid-wide Nature hit plus a 60-second stacking DoT.
• One is survivable; two is almost certainly a wipe.

Wave set 1:

• Place world markers as shown in the picture.
• Everyone with Plague Froth moves to a marker, firing structured lines of waves in several directions.
• Depending on spawn RNG, it clears most totems or only a few.

Wave set 2:

• No markers: the Wave Caller calls positions live.
• Aim so one wave clears totems on several sides at once.
• A totem glows white when a wave is pointing at it; use that to confirm.

Closing:

• Once the totems are cleared, stack in melee and use healing cooldowns through Imbibe.
• Repeat until he dies. Clearing totems is the entire fight, so don't get lazy about moving.