Tank: Keep him still and pull the small spiders in tight onto him so the group can hit them together. They have a frontal poison cone and a web effect.
Dps: Clear the summoned spiders quickly with area damage; stay behind the boss to avoid their frontal poison.
All: Interrupt him the moment he begins eating a corpse. Devour is a large self-heal that prolongs the fight.
Tank: Chain or pin the spiders onto her without dragging her around the room. Interrupt any that try to feed on a corpse.
Dps: Damage the spiders on the boss with area attacks, and interrupt any feeding on corpses before they heal.
Tank: She rears up and hits the aggro holder hard. Block it, or be knocked down.
All: She leaps to a random player for heavy damage and a knockdown. Stay stacked so she cannot leap across the room; if she jumps to you, block or dodge in place rather than running, then return to the boss.
Tank: Hold the melee adds immediately, then chain the ranged ones in and keep Cerise still and facing away.
Dps: Kill the healer and mage adds first, as they out-damage the boss, and interrupt their casts.
All: She winds up a clearly telegraphed heavy attack. Block it. It does not kill a blocking tank, but it kills a DPS instantly.
All: Interrupt her stun and immobilise channel before it lands. You can Break Free if caught, but stopping the cast is cleaner.
All: Stay out of the fire circles on the floor; the damage accumulates quickly.
Tank: Hold Rabbu and drag every add into the centre of the room; interrupt the casters.
Dps: Kill the adds and interrupt the ranged enemies before committing to the boss.
All: He chains a player to him, similar to a Dragonknight pull, and usually follows with a light attack. Block on landing, then step back into position.
All: He telegraphs a long straight strip and charges down it. Step out of the lane. A non-tank who takes it goes down; a blocking tank survives.
Hard Mode: Invoke the Scroll of Glorious Battle on the floor to the right, just before the boss room, before engaging her.
Tank: The room starts crowded. Pull everything back into the doorway for a tight cluster before anyone steps toward the centre; walking in early aggros her.
Dps: Kill the adds in the doorway cluster first. Do not run into the centre early, or you pull the boss.
Tank: A plain melee hit on the aggro holder. Block it every time.
All: She pulls players to the centre and briefly stuns them. This almost always leads straight into Daedric Explosion, so react immediately.
All: A large expanding ring, usually just after Web Pull. Be outside it before it reaches full size, as it is lethal. Move out, then move back in once it ends.
All: DPS and healer stand in a wide triangle, never stacked. When she targets you she fires a projectile; dodge-roll it. If it hits, you are stunned for three seconds, then a web blast lands that can kill a DPS or healer outright. Always keep stamina for this.
All: Hard Mode adds no new mechanics: more health and much harder hits. Positioning, dodge timing and clearing the full Daedric Explosion all become mandatory rather than forgiving.