My guild has finally made it up to the Lich King himself and spent some hours trying to wrap our minds around the fight. Preparing by reading tactics and watching other people do the fight can only do so much. There will still be some parts of the fight you simply have to learn by doing, at least that is how it works for me. Sorta like having to build something yourself before you know how it really works. We haven't downed him yet or the post would've been named "OMG LK DEAD OMG!". We've managed to get to the second phase at best and there are some things that are quite crucial to think about each phase. If you get those right it'll work smoothly. So now we're taking babysteps forward, learning each new crucial part by trial and error. Now this will be from a healers point of view, since I've only ever healed it so far, but there is something in here for anyone interested in whacking the old LK some day, I promise!
There is really only one thing you have to get right in phase one, and that is the handling of Necrotic Plague. As a MT you don't have to do much. Just remember not to grab aggro from the Shambling Horrors, because they're supposed to be tanked by the OT. The OT will stand some 30 yards away from the MT and tank the Shambling Horrors. Whoever gets the Necrotic Plague has to run to the back of the Shambling Horror asap and be cleansed by some designated cleanser. Phase 1 completely revolves around getting this done properly. The disease deals damage every 5 seconds for 15 seconds and then it jumps to a new targets. By having this disease jumping between two Shambling Horrors (or a Shambling Horror and a ghoul before there are two Shambling Horrors) you can kill them very fast. Trying to have dps kill the Horrors is a bad idea since they have hp like some raid bosses.
The tanks will take most of the damage in this phase. The Shambling Horrors go into an enrage where they hit for around 30k dmg on an ICC geared tank. You can either have someone remove the enrage, like a hunter or rogue or have the tank stand it through with some cooldowns. Both tactics work, but of course having a hunter removing it is the absolutely best option.
The designated disease cleanser (in our tries it was me) will have to keep an eye out for the Necrotic Plague. It can't stay for longer than 4 seconds on any player or they will die (unless they are lucky enough to resist half the dmg, which has happened). This means it has to be cleansed even if the player isn't behind the Horror, but of course this will make things alot trickier. The disease will probably jump to another player, you will have to continue cleansing and all these gcds can't be used for healing which of course is bad. Also if there is no disease on the Horrors they won't die and they have to be dead before phase transition. Phase 1, like mentioned, is all about everyone getting the handling of the disease done properly. If everyone reacts in time and gets it to jump to the Horror, and the OT makes sure to keep it between two mob target so that it keeps on stacking, phase 1 will be really easy.
The only other thing to think about in this phase is the Infest debuff. It is placed on the entire raid and will keep on doing damage until the target is healed above 90% hp. In phase 1 this will be cake and really not much to worry about. In later phases this could be more troublesome because the raid will have taken more damage from other things (there is nothing that deals damage to the raid in phase 1 ecept Infest itself) and the healers attention will be quite scattered. Also a healer could be caught by a Valkyr, not being able to heal at all. But that is for later phases, in phase 1 there is really only one thing to think about, and that is the Necrotic Plague. I say it again and again because it's important! ;)
Make sure all Shambling Horrors are dead before you take LK to 70%. Because when he reaches 70% the first transition phase starts, and you don't want any Horrors there. If there is a Horror up and LK is closing to 70%, have everyone wait with damage until he dies (ranged can start shooting on the Horrors if they like, and don't have mana issues). Don't have melee go fighting the Horrors since you don't want the Necrotic Plague jump to any player. New Horrors might rise, but hopefully you'll be able to nuke the last percent to start the transition before it spawns.
Immediately after the last Horror has died and you've nuked LK to 70% he will run to the middle of the platform. That is when you run out from the middle of the platform. He will channel an ice aoe that deals damage to anyone within 45 yards of him, so of course you want to stand as close to the ledge as possible.
Ice Spheres will spawn from him and slowly travel towards one player in the raid. Do not get close to them as they will knock you off the platform! Have ranged kill them. They're easy to kill so even one ranged can handle them alone (in 10 man).
The troubling part of this phase are the Raging Spirits that spawn. They spawn from a random player in the raid and the tanks need to tank these up fast and they need to be killed fast. They do alot of damage first of all, and secondly they do a frontal cone attack called "Soul Shriek" which will damage and silence anyone it hits. You will want to dispel it from a tank, since they can't taunt (and do some other skills depending on class) if they're silenced. But you probably know that already. As a dps make sure you don't stand in front of these Raging Spirits so that you won't be hit by this cone.
After 60 seconds the outer rim of the platform will collapse. You will want to kill any Raging Spirits still alive asap and run into the middle of the platform (to LK) as soon as LK has stopped channeling his ice aoe (Remorseless Winter).
Welcome to phase 2. We haven't gotten much further than this. Now there will be alot of damage going all around the raid. Huddle in the middle and wait for the valkyr to come. As soon as it does, any range will spread out (about 15 yards apart) and any dps will start nuking it.
Be ready to run from Defile. It is an aoe placed on the ground underneath one random raid member, who has to move away from it asap. No one must come close to it as it grows and deals more damage depending on how many people it damages.
Some of the reasons we failed (the times we managed to get to phase 2, because we had troubles with the plague handling at first) were;
- Too many Raging Spirits still alive, killing the tank that tanked them because one healer was targetted by a valkyr and one was targetted by defile.
- Defile under the valkyr which quickly spread because we had a very melee heavy raid.
- Valkyr bugging out flying too high for anyone to dps it!
- One player getting wow-error midfight. Not much to do about that one though ^^
It is a really fun fight however and I look forward to trying it again. Each wipe you feel like you've learned something new and can tweak yet another part of your playstyle. And I hope nothing bugs out next time we try, damn cheating game...