Sindragosa killing strategy

After you heal Valithria to full health, she wipes the Scourge armies so you can move on to the next boss. Sindragosa is the last boss standing between you and the Lich King, but you’ve got to bring down Rimefang and Spinestalker before Sindragosa spawns. Basically, use a tank and spank approach for Rimefang and Spinestalker. Stay out of the icy patches on the ground during the fight against Rimefang. All melee DPS should stay next to Spinestalker during that part of the battle to avoid Tail Sweep and the very strong melee swing.

As soon as Sindragosa spawns, start your 10 minute timer. You have 10 minutes to take her down before she enrages and wipes the raid.

Sindragosa hit points: 11,560,000 (normal)
Sindragosa Boss Abilities

Cleave

Adds 50 to all normal damage
Affects up to 10 raid members

Tail Smash

11,250 – 18,750 damage
Physical damage
Knockback

Frost Aura

4,500 damage every 3 seconds
Frost damage

Icy Grip

Drags all raid members to her in preparation for Blistering Cold

Blistering Cold

35,000 damage
Frost damage
25 yard radius

Unchained Magic

Causes Arcane backlash after 8 seconds

Instability

2,000 damage per spell cast while you’re under the effect of Unchained Magic
Begins 8 seconds after your spell ends
Stacks up to 99 times

Frost Beacon

Marks which raid member will be locked into Ice Tomb

Ice Tomb

Ice blocks you
10 yard radius around the targeted raid member
454,000 hit points to get you out of the ice block

Frost Bomb

23,563 – 26,437 damage
Frost damage
Affects all raid members in line of sight

Mystic Buffet

Increases magic damage taken by 10 percent
Lasts 8 seconds
Stacks up to 99 times

Sindragosa Boss Strategy Guide

The fight against Sindragosa covers both ground and air. She starts off on the ground. All melee DPS should stay next to her to avoid that nasty tail and all the damage she causes up front also. Every time Sindragosa takes off, she’ll target five players with Frost Beacon. All raid members should take note who’s being targeted, because they will be Ice Blocked next. All DPS switches to the ice blocks to rescue the frozen players during this area phase. While knocking down the ice blocks, make sure you keep the blocks between you and Sindragosa to avoid her Frost Bombs. Also don’t DPS the ice blocks down too quickly, or you won’t have anything to hide behind to avoid the Frost Bombs.
Run away when Sindragosa starts casting Blistering Cold. The cast begins, gives you just enough time to run, and then she pulls you back toward her, so the further you can run from her during the cast time, the better.
Stop all casting if Sindragosa casts Unchained Magic on you. Unchained magic has the potential to kill you if you don’t because you’re hurting yourself while you hurt Sindragosa. Healers can try to heal through this, but the best course of action may be for the caster to stop DPS during Unchained Magic and Instability.
When Sindragosa hits 30 percent life, she stays on the ground and adds Mystic Buffet to her abilities. This last part is a DPS race to burn Sindragosa down before the Mystic Buffet stacks get too high and wipe the entire raid.

Once you guys have read the above texts, this shall further guide you in understanding the Boss fight: