Blood Queen Lana'thel

Health:
10 Man - 18M
25 Man - 62.5M
Enrage: 5min 20sec
-------------------------------------------------------------------------------
Abilities:

Ground Phase:
-Shroud of Shadow - An aura of sorrow and despair emanates from the caster, inflicting 3000 (4500) Shadow damage every 3.0 sec. to nearby enemies. Instant
-Presence of the Darkfallen - Increases the damage of Shroud of Sorrow by 5% for every vampyr in the room (likely Hard Mode only).
-Blood Mirror - 100% of damage done to linked source is reflected to you as Shadow damage. This affects the person closest to the tank.
-Delirious Slash - Inflicts 50% of weapon damage to an enemy and causes it to bleed for 5250 to 6750 damage per application every 2.0 sec. for 20 sec. 10 yd range. Instant (appears to not stack and only on the OT in normal mode at least).
-Pact of the Darkfallen - Deals Shadow damage to you and nearby non-linked allies. This effect expires when all linked targets are within 5 yards of each other. 100 yd range. Instant
-Swarming Shadows - A swarming void consumes the target, causing a mass of shadows to appear beneath the target every 0.5 seconds. 100 yd range. Instant
-Twilight Bloodbolt - Hurls a bolt of dark blood at the target, dealing 9250 to 10750 damage to the target and surrounding allies within 6 yards. Unlimited range. Instant
-Vampiric Bite - Deals 12025 to 13975 damage to the target, granting them the Essence of the Vampyr Queen. 100 yd range. Instant
-Essence of the Vampyr Queen - Increases damage by 100%, and causes attacks to heal the player for 15% of the damage done, as well as cause no threat. Causes Frenzied Bloodlust after 60 sec.
-Frenzied Bloodlust - The caster must satiate their need for blood [within 10 or 15 seconds], otherwise they will lose their will to Queen Lana'thel. You gain Vampiric Bite on your action bar when you're under this effect
-Uncontrollable Frenzy - Mind Controls a player in the raid. Increases damage done by 100%. Health increased by 300%. Increases healing done by 1000%. Unlimited range. Instant
-------------------------------------------------------------------------------
Air Phase:
-Bloodbolt Whirl - Summons a maelstrom of whirling Bloodbolts, every 2 sec for 6 sec. each one can cast Twilight Bloodbolt (see above).
-------------------------------------------------------------------------------
The Fight:
This is a 2 tank fight, with alternating "air phase" and "ground phase".

-First off, there's Shroud of Shadows, which is just a damage aura in the room. Raid heal through that.
-The tanks will be affected by Blood Mirror, well the MT and the person closest to him. What it does is link the 2, and for each damage done to the MT, it transfers over as shadow (mostly) damage to the OT. It does not appear to be resistable in any way, so healers just keep the both of them up as they'd be hit the same.

-Twilight Bloodbolt is someone she fires at people doing splash damage around the person it hits. So it's the spread out mechanic for the ranged. Like Vile Gas, Blood Nova, and many others, spread the fuck out.

-Pact of the Darkfallen is like Mother Shahraz's Fatal Attraction, you know, where 3 players get linked, they do damage to each other unless they run away from each other. Except you run to each other, so more like Yogg's Brain Link, in this manner. You have to be within 5 yards of each other, though I believe it takes a second so you'll probably just wind up stacking on each other. Only 2 are linked in 10 man.

Swarming Shadows is the new Legion Flame. But purple, and all shadowy. You get it, you move, leaving your fire trail somewhere away from the raid preferably.

On some timer or something, she'll fear the raid and fly up into the air "phase". All she does is summons Twilight Whirls which in turn, fires Twilight Bloodbolts at us. All of us. Same ability as above, the whole splash damage everyone around you. So the raid has to spread out after the fear wears off. After 10-15 sec, she'll come back down, we resume the fight.

Anyways, that's all for the damage portion of the fight you have to heal through. And yes, it's a lot of damage. Now for the "fun" part, a major mechanic that you need to even kill the boss before her enrage of 5min 20 sec.

15 sec into the fight she'll randomly (or maybe not so random as theories of threat used for target) a player with Vampiric Bite. This well does damage, but more importanly it turns you into a Vampyr granting the Essence of the Vampyr debuff.

What that does is increase your damage done by 100%, do zero threat, and heal yourself for 15% (10% in 10) of your damage done. So, this is a massive DPS buff. It lasts for 60 seconds (75 sec in 10 man) before giving you the debuff of Frenzied Bloodlust.

That will put you in a vehicle of sorts, replacing your action bars with Vampiric Bite, and Vampiric Bite only. What you're forced to do is bite another player, another non-vampyr player. So 1 becomes 2, 2 becomes 4, 4 becomes 8, 8 becomes 16, etc. You have to pick another DPS to bite, and you have to be in melee range to bite. You will want to organize propgating this to your best DPS first to get the most out of the Vampyr buff. It'll be the best way to beat the 5 min 20 sec enrage timer.

Should you fail to bite someone, either by hardcore failing, or running out of people to bite due to deaths (hotfixes have prevented a soft enrage of running out of people as long as long as people are alive). You gain Uncontrollable Frenzy, which is a boss MC, you do more damage, have mroe health, and heal for a fuck ton more. Yea, you die now if you fail.
-------------------------------------------------------------------------------
https://www.youtube.com/watch?v=ZdRvXHzSDD0
http://www.downfallguild.org/Blood-Queen-Lana%27thel
If you have any question, feel free to ask them below.