Lemmings of the Light

(boss tactics write-up by Kachi)

Fireball - Inflicts fire damage to an enemy. Deals 11,000-12,000 fire damage. Only used in phase 1.
Wing Buffet - Knocks back players in a 35 yards radius around the caster. 1.5 cast. Only used after breaking its chains in phase 1 (above 50% health).
Flame Breath - Inflicts 13125 to 16875 Fire damage to players in a cone in front of the caster. 2.5 cast. Used after breaking its chains in phase 1, and throughout phase 2 (top aggro is targeted).
Flame Buffet - Increases the Fire damage a player takes by 1000 for 1 min. Is cast during phase 2.
Devouring Flame - Spits a Lava Bomb at a player, inflicting 6013 to 6987 Fire damage and deals 6013 to 6987 Fire damage every second to anyone staying within 6 yards of the explosion. This effect lasts for 25 seconds. Used in both phases; this is only fired at the tank in phase 2.
Fuse Armour - Reduces the armour, attack and movement speed of an enemy by 20% for 20 sec. Stacks up to 5 times. Only used on the tank in phase 2; must be countered by taunting with a different tank.
Berserk - Increases the caster's attack speed by 150% and all damage it deals by 900% for 30 min. Razorscale gains this debuff after 8-10 minutes.

On normal (10 man), the fight proceeds exactly like the 25-man variant, except that only two turrets need to be repaired and fired instead of four.
This boss fight consists of three phases, alternating air and ground phases until 50% damage taken, and then a pure ground phase from 50% to 0%.
Talking to the Expedition Commander will begin the event with Razorscale in her air phase.
Razorscale appears to have two separate Berserk timers, the first applies during phase 1 and 2 when rotating the air / ground phases and occurs approximately 5 minutes into the fight, a second longer one is in operation if she is successfully moved into phase 3 before this. This places a limit of roughly 3 ground phases on the raid.

Air Phase
The air phase consists of defending the Expedition dwarves while they repair the harpoon turrets. During this phase, the focus should be on defeating adds (Sentinels are priority, Watchers must be CC'd and killed second, Guardians last), and staying out of Devouring Flame. As the turrets get repaired one at a time, they can be clicked to fire a harpoon at Razorscale.
Positioning
The raid should be split into two groups in a sort of 'V' shape at the start, with the vertex in the centre of the large circle. Tanks will pick up adds and attempt to kite them back towards everyone else to be Aloe’s. Healers and ranged DPS should be back slightly to avoid whirlwinds and chain lightning. Shaman are very useful in interrupting Chain Lightning and Lightning Bolt, which should help kite them together with the rest of the adds (of course, rogues and warriors will be helpful with that as well). In most cases, watchers will automatically begin melee-ing after a single cast; if you can take the damage, then don't waste time dealing with them separately.
Harpoons 1-3 should be activated as soon as the third harpoon becomes available, with harpoon four being activated as soon as there is no sentinel present (the sustained damage from this add prevents additional healer and tank dps being focused on the boss). DPS should begin to converge into the circle when the third harpoon becomes available to minimise time lost in the ground phase.
During this phase it is important to ensure that the raid healers keep members of their party above 12,000 health as this prevents losing targets to a single fireball or devouring flame; a double or even triple breath is possible (and common) so healing must be fast and effective (Paladins are ideal in this role due to Holy Shock). Healers' first priority must be to keep themselves alive, however any loses in this fight can be detrimental to the raid's ability to beat the enrage timer.

Watching for projectiles
Razorscale's fireballs and devouring flames will annihilate a group that isn't paying attention. There are no addons that currently track either projectile, so it must be watched closely. To do this, have one or two healers, prior to the fight, look up and target Razorscale and then use /focus. Make sure cast bars and target of target can be seen on the focus (test on a player in the group). During the fight, have the healers, between healing, watch the focus for Razorscale's targets. Each target can only be seen briefly, for less than half a second so they have to be on their toes. If no cast bar is shown, but someone is targeted, it means a fireball will hit them (it can miss). Priests can shield these targets, and others can just pre-heal to get them up immediately after being struck. It's important to keep them healed in case they get targeted multiple times in a row. When Razorscale uses Devouring Flame, a 1 second cast bar will appear, and the target will appear right as it finishes. The person who as targeted should be notified immediately, and that person needs to begin moving (preferably away from others in the raid) or be ready to move immediately. The devouring flame will track the target briefly (if you move, it will move) before striking the ground (you can see a blue ball fall into the location before spreading into flame). If you move early, it's hard to know where it will hit. If you stand in one place, you can position yourself safely and then run when the flames are about to appear.

Ground Phase
Once all four turrets have been repaired and fired, Razorscale will be forced to the ground where she will remain stunned for several seconds. Everyone should immediately move behind her, and DPS should focus on bringing her HP down as much as possible while the tanks hold any remaining adds. After the stun wears off, Razorscale will breath then return to the air and begin the air phase again.
For this phase tanks should converge onto the rear of Razorscale allowing their DPS to be added to that available in this phase, with 5s remaining until the stun wears off the tanks should move with any remaining adds towards the furthest point on the circle and allow full raid AoE damage to be applied to the adds. As new pods appear tanks should move their adds back to their regular tanking positions.

Phase 3
Once Razorscale is brought to 50% health, she will land permanently, at which point she will need to be tanked facing away from the group to avoid breaths. The fight from this point is very simple, she will continue using Devouring Flame, she will do a knock back to everyone within 35 yards, and inflict the Flame Buffet debuff. During this ground phase, the DPS should go all out in order to defeat Razorscale before the Flame Buffet debuffs cause the tank to be one-shot.

There is another debuff that happens during this fight. In phase 2, when you are tanking Razorscale around your tanks will get a debuff called "Fused Armour" which adds a slowing effect to the tank. When this debuff hits 5 stacks the tank can't move or use any abilities, including taunt. You need to change tanks when the debuff gets to 2 stacks in order to finish the fight.