Originally Posted by LoreWelcome back to the Tier 14 Raid Guide. My name is Lore, and in this video I'll be showing you the 25-man normal version of the Tsulong encounter. This is a relatively technical two-phase encounter that's actually somewhat reminiscent of the Valithria Dreamwalker encounter from Icecrown Citadel. You'll need 2 tanks, and 6 or 7 healers, although due to the fight's mechanics it's okay to bring extra healers if you find it necessary.
Tsulong alternates between two phases: a Night Phase and a Day Phase. He starts the encounter in the Night Phase, so we'll talk about that one first.
The first and most important mechanic in the Night Phase is the Dread Shadows debuff. He'll apply one stack of this to everyone in the raid every 2 seconds, which deals a small chunk of Shadow damage. However, that amount increases as your stacks get higher. To deal with this, you'll need to step into a Sunbeam to clear your stacks. Tsulong will summon these in random places around the room, and stepping into a Sunbeam immediately clears all stacks of Dread Shadows on a player.
However, you can't simply have everyone stack up inside the Sunbeam, for two reasons. One is that the longer you stand in the Sunbeam, the smaller it gets, until eventually it disappears. If that happens too early, you'll have no way to clear your stacks, so you only want people to step in and out of it briefly -- just long enough to clear their stacks and get away.
The second reason is another ability he casts called Nightmares. This is a large circular void zone that, after a few seconds, will deal a large amount of Shadow damage to everyone standing inside of it, and also fear them for a couple seconds. Dealing with this should be pretty obvious -- just don't stand in the big purple swirly things.
Ideally, you'll want to position Tsulong relatively close to the Sunbeams as much as possible. However, that can be a bit tricky, due to his final Night Phase ability: Shadow Breath. This is a frontal cone breath attack that deals a large chunk of Shadow damage to anyone standing in front of him and also applies a 100% Shadow damage debuff. You don't want this to hit the raid, for obvious reasons.
On top of that, since the debuff not only increases the damage of Dread Shadows but also Shadow Breath itself, you should be aiming to have your tanks swap aggro immediately after Shadow Breath is cast. Whichever tank is currently not tanking should be standing near the Sunbeam, ready to reset their Dread Shadows stacks and then immediately run over and taunt the boss. Fortunately, the Shadow Breath debuff is short enough that no tank should ever have to take two breaths -- you'll safely be able to swap after each breath, every time.
Okay, that's pretty much it for the Night phase. Just deal with those few, relatively straightforward mechanics, and put as much damage into the boss as possible. Lets move on to the Day Phase.
After two minutes, Tsulong will regain control of himself and switch into the Day Phase. This phase is a bit more complicated. He'll become friendly, and his health will actually reverse -- so if he was at 75% at the end of the Night Phase, for example, he'll be at 25% health after switching to the Day Phase. Now, you can finish the encounter by either bringing his health to 0 in the Night Phase OR healing him up to 100% in the Day Phase. So, healers will want to immediately start spamming as much healing on him as possible.
Meanwhile, several types of adds will start spawning around the edges of the room. The first will be a very large add called an Embodied Terror. These will need to be tanked, and will also occasionally cast Terrorize on either a random raid member or on Tsulong himself. This is a pretty heavy damage over time effect, so you'll need to dispel it immediately, especially off of Tsulong as it will deal 2% of his health in damage every 2 seconds. Remember, you're trying to get his health as high as possible during the Day Phase.
Once an Embodied Terror is killed, it will spawn a handful of Fright Spawns. These are very small adds that just need to be grouped up and AOE'd. They do cast a short fear from time to time, but generally speaking should die quickly enough for that to not be a major issue.
The final type of adds are the Unstable Shas. These will spawn around the edges of the room and start to move towards Tsulong. If they reach him, they deal a very large amount of damage to him. Again, you're trying to heal Tsulong right now, so you'll want to kill these before they can get to them. They'll also cast Unstable Bolt at random raid members, which deals a fairly substantial amount of damage, but also causes them to lose 15% health every time they cast it. Generally speaking these will need to be handled by your ranged DPS while melee worries about the Embodied Terrors.
Fortunately, Tsulong will also help you out a bit during this phase by casting a Sun Breath. This is a good thing to stand in. First off, it deals a heavy amount of damage to any adds it hits, so tanks will want to bring Embodied Terrors and Fright Spawns in front of Tsulong as quickly as possible. Secondly, it will actually restore 25% mana to anyone it hits, as well as increasing healing done by 500% for 6 seconds. That means that right after a breath is the best time for healers to pop any healing cooldowns they can. Guardian Spirit is especially useful here if you have a Holy Priest. And since it restores mana, that means your healers can go pretty much all-out through all of the Day Phase as long as they're making sure to stand in the breaths.
Of course, healing isn't solely limited to the healers here either. Any time that a hybrid DPS or even a tank has a second to throw a heal at Tsulong, they should. He can even be bandaged. After two minutes of Day Phase he'll go back into the Night Phase, and his health will once again reverse, so any healing you can do during the Day Phase is essentially DPS done in the Night Phase.
You'll have a total of two Night Phases and two Day Phases before hitting the enrage. During progression, this can actually be a pretty tight enrage, so make sure everyone's doing everything they can to either DPS the boss during nighttime or heal him during daytime. Once you've got the mechanics down, Tsulong is actually a really fun encounter that really rewards out-of-the-box thinking from your raid team.