This is one of the harder strategies to wrap your brain around as a DPS. This is the opposite of a DPS fight - this is a do your job and turn off the meters fight.
Now, there is so much going on in this fight, it is quite likely I will forget something - please let me know and I will update as we go along.
2 tanks (one for Taldaram - hence forth known as Edward Sparklypants, and one for Valanar)
1 "other" tank (usually a warlock - for Keleseth)
good mix of range and melee DPS
The pull is straight forward, each tank picks up their assigned mob and moves them apart from one and other. The trick to this fight is that one Boss is Active with the red swirly crap at a time. They will be the one with a health bar, and they are the one with the special ability active. They are the one you need to attack.
Before I get into each trick for each boss, there is something that needs to be made so painfully clear you would think you had a wasp sting you nose (don't laugh, I had to AFK recently to rescue someone who had that happen to them). This is not a DPS race, this is a survivability and raid coordination fight. There will be some people at the bottom of the meters who usually sit at the top. This is perfectly normal. I cannot stress enough that you do your job and you do it with 100% uptime.
With that in mind, let's look at the bosses one at a time.
This dude is tanked by the range tank, usually a warlock. Keleseth creates floating purple balloons that the range tank has to run around and collect (with aggro) while keeping Keleseth interested in them and no one else. They need to collect as many as they possibly can, as each balloon channels Shadow Resonance into its target. Yes, it stacks.
The other annoying thing Keleseth does is throw lances around whoever has its aggro. The sooner that range tank has 2-3 balloons, the better for the healers.
Note to healers: this tank will be taking large damage early on from the lances until they can collect a couple of balloons. Make sure they are all healed up and watched carefully. I recommend this as a bacon target for a pally.
Keleseth is pretty straight forward: Collect balloons, keep threat.
Edward Sparklypants is the only one allowed to be in front of this guy, so tank him off to the side facing away from the raid or he will turn more people into Edward than we really need to see in a raid (we already have 3 emo vampires in this fight, more than one emo sparkly vampire tank is just too much for the healers to deal with!).
Taldaram also throws balls of fire around the room, which explode on impact with their target. Fire resistance totems/aura will help here.
This guy is all about the physical shock factor. No resistances will help you with this more than SPREAD OUT!!!
He will create glowing yellow balls in the sky that slowly descend to the ground. Allocate a hunter, or a mage or someone whose sole job it is to keep these buggers from hitting the ground. When they are hit with damage, they go up in the air again. If one of these suckers hits the ground, it will pretty much knock everyone flat on their backs and *points* over there, which stuffs up all the careful positioning, you will have set up to get through this fight. So, keep these things in the air at all costs. It is easy to do, and the consequences of NOT doing it are dire and onflowing.
Valanar will also place swirly white things randomly in the room, if you arewith 12 yards when they go off you will get knocked on your arse again. So, when you see the white swirly near you, make sure you move away. This is where range finder mods are very very useful. Keep an eye on yours.
Red Swirly Valanar
Let's take this backwards.
When Valanar is empowered (which means he has a health bar, and is the current DPS target) his vortices also become empowered.
Instead of placing a couple of white swirly things in the room you need to move away from, everyone becomes their own little vortex. Everyone needs to spread out at least 10 yards apart to ensure that you dont cop multiples of 7k damage. It doesn't take much for you to die to this.
This isnt a difficult mechanic to understand, but it is REALLY hard to get right. It relies on everyone knowing what they are doing, have some idea of where they need to be and also having range finders (either your eyeballs or a mod of some kind) telling you that you are far enough apart from the people near you.
Often, to minimise movement for the healers, they are allocated the semi circle at the bottom of the stairs so they have range for everyone and an easily defined space for them to be in. Everyone else spreads out outside that.
Red Swirly Taldaram
Taldarams empowered ability is his fireball. The rule of thumb is the bigger the ball, the harder it hits, and this one starts our HUGE. Fortunately, it also likes to smash people it goes past and that bleeds of fire to do which makes it smaller. Now, this fireball will hit you really hard if you dont reduce its size by having it hit people as it goes along. Generally, you have rogues sprint along with the fireball, taking damage and making the final impact lessened. If you have issues with this, make sure other DPS run in and take some of the damage away.
Having rogues able to do this is easy because this will only happen when Taldaram has a health bar and everyone is attacking him.
Red Swirly Keleseth
Keleseth's empowered ability is his lances. They hit like mack trucks if the ranged tank is not holding enough balloons. As long as the range tank has aggro and is continuously collecting balloons, then this part of the fight is quite straight forward.
Slowly, slowly is the key to this fight. Make sure you keep those kinetic bombs in the air, that everyone knows where to spread to when vortices are about, and that the fireball has its power bled off by people being in range to be hit as it speeds along.
The very hardest thing is spreading out. There is not a lot more I can tell you about that, it is, unfortunately, a bit of a retard check as well. And yes, one person can wipe the raid.
Healers, there is a lot of damage going around in here, so pay attention and make sure that you keep your space at the bottom of the stairs to be yours so you dont have to worry about moving for vortices.
Shadow resistance and fire resistance is very helpful.
Wipes are generally from the following things:
1) the range tank not having enough purple balloons
2) the range tank not getting heals early on when there are not enough balloons to help mitigate damage
3) healers getting knocked over (either not moving themselves, or someone moving into them) and therefore tanks dying
4) kinetic bombs hitting the ground because the people allocated to stop them is not doing their job
5) People dying to the empowered vortices by not spreading out enough
6) Empowered fireballs not getting bled off enough
If you have that list covered off, you should be well on your way to getting these guys down.