Well, after spending an inordinate amount of time wiping on this boss the other night, I think I have a REALLY good grasp of how to write this one up. For the record, this is the ultimate in noob fights. Super simple mechanics that every man and his worg will get wrong, and it only takes one person to stuff it up and cause a wipe.
even distribution of DPS, all with working microphones
BQL comes in 2 phases, on the ground and in the air. She will have 2 air phases before she enrages and smears your entire raid into paste on the ground. That's 5 minutes people!
The tanks run in (with appropriate MDs etc) and keep BQL on the stairs. Turn her to face the back of the room. She will instantly cast a Shroud of Sorrow on everyone in the room. This will keep the healers on their toes.
Ranged and healers need to spread out evenly around the room or you this will kill you and your stacked up buddies. So just spread out nice and evenly - in fact, spread out as per where you will be for phase 2. Melee and Holy Pallies stack directly behind BQL at max hitbox range.
Cast your mind back to ToC and to Jaraxxus. The flamey thing that you had to run around the room screaming whilst on fire? That's back, except this time it is purple and called Swarming Shadows. When you get it (your favourite boss mod will scream at you, be that your RL or something on screen or both) you need to run around the OUTSIDE of the room as close to the wall as possible, to ensure that everyone has as much room as possible for phase 2. DO NOT stand still or you will die and be ridiculed by your raid team. Even running in the wrong place is better than not running at all. But yes, ideally, get that fire around the edges of the room.
Next, again cast your mind back, this time to Yogg Saron. Remember when you and someone else were joined together with the bright green bonds of insanity? Well another similar mechanic is in play here. This time the bonds are bright red, and explode with an aoe every second or two until you run and give the people you are joined to a hug in the middle of the room. In 10man it's 2 people, in 25 it's 3 people. The best way to deal with this is to have everyone affected run to the diamond floor pattern on the floor in the middle of the room. The AoE is nasty, so again, you need to move as fast as possible to the centre.
Now I have explained the two phase 1 mechanics that are simple, I am going to delve into ones that are not, and are still not really understood.
The tanks are sharing damage, or they should be. The tank (ie one with aggro) will have an ability on them called Blood Mirror. The toon physically closest to you will share all the damage that you, as the tank, take. This is a good thing because BQL hits hard, but nothing that an appropriately geared Holy Paladin or two can't deal with (with good backup of course).
A short time after Blood Mirror is up, BQL will go bite a toon (because she is a vampire and all). And thus begins the most confusing part of this fight. That toon will have the buff Essence of the Blood Queen giving you 100% extra damage and will heal you for 15%. However, it also has a downside. After 60s, you gain the debuff Frenzied Bloodlust. In short, you have to bite someone to satiate your lust for blood drinking, now that you are a vampire. You have 15s to get to another toon and use the vehicle bar now on your screen to bite them. You cannot bite anyone that is already bit, so I highly recommend getting raid frames that support you seeing the Blood Queen buff so you don't try to bite someone already affected. Why is this an issue? Because if you don't bite someone you will become MC'ed and almost certainly will cause a wipe at this stage in progression.
Tips about the first bites - get the first bites onto your highest DPS. Now, I have spent a lot of time recently trying to figure out who gets the first Vampiric Bite. There are plenty of theories going around the net, ranging from threat, to who hits BQL first after blood mirror. I have looked through logs and logs, and honestly, I cannot really see a pattern to who gets it yet. When I do see a pattern, I will let you all know. Hell, even I, as a healer, has managed to get bit first. It has something to do with threat, something to do with when you hit her as well. The best bet if you want to try to control who gets the bite first is to get everyone to hold DPS except the tanks and the person you want to get bit. Let them establish the threat table and hits in first by holding off for 4 or 5s.
Get raid frames that show the buff clearly and a working mic in vent/TS. I cannot stress this enough. If your target is bitten, you will need to find a new target and quickly. Call it out on vent and establish who you are biting as soon as you can. There are mods you can get to help your raid team work out who is getting bitten when, I don't use them, so I cant tell you what they are. We call our targets early on in vent and make sure people don't screw it up.
The first biter - bite as soon as you can to ensure that people do not have to try to do bites during phase 2 (you will understand why when I describe it). If you are looking like you need to bite during phase 2, either get your bite off early, or try to wait until after it is over (risky, but again, call this out on vent if you are worried). If the first bite is timed right, you shouldn't need to worry about this.
So you understand the math, this is how the bites approximately progress during the fight (note the big fat APPROXIMATELY ymmv due to vagaries of when people actually bite in that 15s window):
0:15s 1 buffed (BQL bites someone)
1:15ish 2 buffed (1 bit another)
2:00 Air Phase
2:10 Ground phase
2:20 ish 4 buffed (2 bit 2 more)
3:25 ish 8 buffed (4 bit 4 more)
3:40 Air phase
3:50 Ground phase
4:30 ish 16 buffed (8 bit 8 more) all your DPS should have the debuff at this stage.
Enrage - there should be about 9 people unbitten who can be used as "spares" for stuff ups.
BQL will swoop up in the air and cast a fear on everyone. Tremor totems here are invaluable, also any other "get out of fear free" ability you might have helps. Positioning in this phase is crucial, and you don't have a lot of time to move.
As for Blood Princes' vortices, this is a "spread out or die" mechanic. All the healers and ranged should know where they need to stand for this already, as they would have already copped the extra damage in phase 1 if they didn't. Now, the stacked melee need to find their spaces. The tanks can stack on top of each other where they tank the queen, and all the melee need to spread out around the platform, making sure they have 6 yards between them. Using your favourite range checker (your eyes or a mod) ensure you get away from anyone after the fear. If you are having trouble with this, crack out MS paint and draw a picture and allocate people to positions. Again, simple mechanic, but one person in the wrong position will wipe out a heap of people, and probably cause a wipe.
When phase 2 is done, melee collapse back into their phase 1 positions.
So, why are we wiping?
Are you spread out enough in phase 1 and 2?
Are your healers keeping up (it's hard yakka early on)?
Is anyone getting MCed?
Is anyone dying early with the debuff meaning the damage increase is not going out to enough people?
Are people trying to bite the same targets?
Are people simply not paying attention on vent, or not talking when something goes wrong?
I think this fight is actually simpler than putricide, there is just so many more places where people can wipe the raid which make this a very frustrating fight. Be careful taking new people in on this once you have it under control - even one new person can throw the whole balance out and give you a night of frustrating wipes where the week before you one shot it.