Two phase fight. On Normal, the boss cannot throw you off the edge.
In P1, you follow the boss as it periodically ascends to multiple platforms.
P2 starts when the boss reaches the top platform.
You fight the boss on a platform. Periodically, it will ascend to a new one. You follow her by climbing the ramp.
MOVE OUT OF WEBS
AND LIMIT YOUR STACKS
TO THE MINIMUM.
Several players are debuffed and drop webs at their feet for 6s. Standing in webs applies a 25% slow. Reaching 10 stacks slows you by 75% for 30s.
USE SPIDER EXPLOSIONS
TO REMOVE WEB EFFECTS.
STAY AWAY OTHERWISE.
MOVE FAR AWAY OR
STAND IN WEBS TO NOT
GET PULLED OFF.
The boss pulls everyone inward. Slows from webs reduce the pull, and standing in the webs will fully negate it.
Players who are pulled all the way in are slowed by 75% for 30s.
SPREAD WHEN YOU
HAVE THE CIRCLES.
DODGE THE SWIRLS. ICE
ON THE GROUND IS SLIDY.
Swirls mark areas where ice will land. They leave behind ice patches which deal ticking damage and make your character slide around slightly.
DON'T STAND IN FRONT
OF THE SPIDER.
Frontal cone on the tank that deals a lot of damage. Also leaves behind ice patches.
Big spiders keep buffing themselves and deal ramping raid damage, making them a priority target.
Once the boss reaches the 4th and final platform, P2 begins. The floor is slippery. Watch your step!
SPREAD. AVOID TOUCHING
PLUMES ON THE GROUND.
All players are debuffed with a circle that will explode after 5s.
Leaves behind plumes that will knock back and damage anyone who touches them.
POSITION YOURSELF BEFORE
ENTANGLEMENT TO NOT GET KNOCKED
INTO PLUMES OR OFF THE EDGE.
Several players are debuffed with a 6s DoT and drop webs, then knocked back and slowed by 75% for 30s.
Try to avoid being knocked into plumes or off the edge!
STAND IN WEBS SO YOU
AREN'T KNOCKED FAR OR
OUTSIDE THE PLATFORM.
The boss deals damage and knocks everyone back. Standing in webs will negate the knockback.
Don't get knocked into plumes or to the edges of the platform.
USE SPIDER EXPLOSIONS TO
REMOVE WEB EFFECTS.
Lower platform levels will deal increasing ticking damage to those on them.
PULLED INTO DEATH
Upcoming most emblematic source of death in this raid: Getting pulled off the platform by the boss in Heroic. It can happen very quickly.
Properly set up your boss mod to play a very identifiable sound when the ability is cast. Spot webs on the ground ahead of time or be far from the edge before the end of the cast.
SPIDER ADD BREATH
The spider add in P1 frequently casts a breath cone that packs a lot of damage.
Avoid standing in front of the add and set up your boss mod to properly scream at you when the add casts the ability (especially if you're a melee).
P2: Pushed off of the platform
Another Heroic upcoming emblematic death source is the burst off the platform, an immediate death.
Configure your boss mod to play a noticeable sound before the ability happens. Try to keep your back facing a solid patch of land during P2.
P2: Knocked off the platform from the debuff
After dropping webs on the ground, Sennarth knocks you back. This can quickly lead to death.
Make sure your boss mod properly alerts you when you are targeted by this debuff, and always have the platform at your back before the debuff expires.
P2: Plumes can knocks players off the platform
Walking on a plume knocks your character back. This, combined with the raid knockback or the cocoon debuff, can create devastating combos.
A general WeakAura pack that provides "icon" style mechanics/debuff as well as short descriptions for each. Pretty standard. We also recommend downloading Causese Sound addon to hear vocal announcements. Feel free to thank the amazing Causese here (sorry, no Twitter that I know of...).