Anduin Wrynn is a 3 phase fight with two intermissions.
We split the raid evenly to deal with an upstairs/downstairs mechanic during the first and second phase.
While upstairs, will deal with Blasphemy, Befouled Barrier, and Wicked Star. Blasphemy marks some players with a yellow debuff and some with a purple debuff. To purge this, yellows stand still and purples go run into them. If a purple and a purple or a yellow and a yellow touch, those two die, and then there are two of the opposite color that can't purge, so those other two die eventually too.
Befouled Barrier puts a shadow circle on the ground that we need to stack inside of and spam heals to handle; as we heal, it shrinks, so you may need to reposition. Standing in it reduces healing received so if you actually need to heal, you need to step out and get topped off. If this isn't handled we take big raid wide and probably wipe.
Wicked Star is a run out of the raid laser that will shoot out and then bounce back to anduin, silencing you if it hits you--run it out of raid and everyone else dodge the silver line.
Anduin will do a big black frontal cone, Kingsmorne Hungers, twice during phase 1 and phase 2. If hit by this, you go downstairs and if hit by it twice in a row, you die, hence the group splitting.
When downstairs, there will be four aggressive Anduin's at skulls that walk towards center, and four friendly anduins at star that walk towards skull. Healers need to fully heal friendly anduins before they reach skull. DPS need to kill the aggressive Anduins before they reach star, which can/should be CCed as needed. Tanks will pick up a big shadow elemental that also needs to be killed--ideally the tank stacks it on the active anduin target and it gets cleaved down. This basically needs to be handled perfectly or we wipe.
In the intermission, we fight the Lich King and a fuck ton of adds. There will be an abomination that begins casting Kill The Raid that we will hard swap to and burn and the second time around, there will be moving walls of zombies we dodge. We lust first intermission.
In phase 2, everything repeats and Anduin also periodically summons 3 adds upstairs at 3 of the 4 skull positions at random. These adds will cast Wipe the Raid, and must be CCed and focused down. We'll call an active target, hard CC the inactives, interrupt and burn the active, and rotate through the room. These adds cannot be hit by Wicked Star or else they get buffed with Absolutely Definitely Wipe the Raid, so we'll position and handle that accordingly. Upstairs/downstairs happens, second intermission happens, we go into phase 3.
In Phase 3, only Wicked Star repeats and Blasphemy is modified. There will be yellow in the center and some players will be marked with purple DoT. Moving to yellow purges, but deals raidwide, so purples need to purge slowly to avoid wiping raid. Other than that we cast kill boss repeatedly.