The encounter against Tsulong is a two-phase fight. The first is the Night Phase during which Tsulong is hostile. The second phase, the Day Phase, Tsulong is friendly, and your raid must heal him, while protecting him from various adds. Each phase lasts 2 minutes and is indicated by his energy bar.
Tsulong's health is reversed each time a phase change occurs, so that the amount of health that is missing from Tsulong's health in the Night Phase becomes the amount of health he has during the Day Phase. Defeating Tsulong is achieved by killing him during a Night Phase or healing him to full health during a Day Phase.
The first phase is always the Night Phase and he enrages a few seconds after the end of the second Day Phase.
During the Night Phase, Tsulong makes regular use of three main abilities.
- Shadow Breath: a frontal cone breath attack that deals Shadow damage and applies a stacking debuff, which increases Shadow damage taken by 100% for 30 seconds, per stack;
- Dread Shadows: a stacking debuff that Tsulong applies to all raid members every 2 seconds and increases the damage that the players take from Dread Shadows by 10%. This can be reset by moving through the Sunbeam Tsulong creates. Unlike LFR, each second that a player stays in the Sunbeam, its radius becomes smaller, until it disappears.
- Nightmares: is cast at the location of a random player which deals Shadow damage to all players within 8 yards of the point of impact, and also fears them for 3 seconds.
- Tsulong should be tanked facing away from the raid, and tanks should swap on every Shadow Breath. The tank currently not tanking Tsulong should NOT be in front of him.
- Ranged DPS and healers spread out at least 8 yards apart, to minimise the damage and fears caused by Nightmares.
- Move out of teh Nightmare ground effect to avoid getting feared.
- Resets your stacks of Dread Shadows at 12-18 stacks by walking through the Sunbeams. DO NOT STAND IN THE BEAM FOR MORE THAN 1 SECOND.
- DPS Tsulong.
During the Day Phase, Tsulong is friendly and needs to be healed he uses 1 ability:
- Sun Breath: a frontal cone breath attack that deals buffs raid members it hits with Bathed in Light and damages any adds it hits.
- Bathed in Light: restores 25% of maximum mana and increases healing done by 500% for 6-seconds.
- Embodied Terrors: large adds that place a dispellable debuff called Terrorize on random raid members and on Tsulong himself.
- When cast on players, Terrorize damages the player for 20% of their current health each second for 10 seconds.
- When cast on Tsulong, Terrorize damages him for 2% of his total health every 2 seconds for 10 seconds.
- Fright Spawns: are small adds that are created when an Embodied Terror is killed, that cast Fright in a cone in front of them, dealing a high amount of damage and fearing all affected players.
- Untable Shas: are adds that spawn around the room and move towards Tsulong. When they reach him, they deal a very high amount of damage to Tsulong before they disappear.
- Have your healers always stand in front of Tsulong, so as to benefit from Bathed in Light as often as possible and heal Tsulong.
- Tank the Embodied Terrors and the Fright Spawns in front of Tsulong so that he damages them with his breath. If done correctly, this will cause all the Fight Spawns to be instantly killed by the breath attack.
- Make sure that the Fright Spawns are always facing away from the raid.
- Untable Sha adds are the top priority, since they must be killed before they reach Tsulong, or else they deal a massive amount of damage to him. These adds cannot be tanked, but you can stun, slow, and knock them back (inc. Death Grip and Gorefiend's Grasp).
- DPS should help heal Tsulong immediately after a Sun Breath if they can cast a heal
- Lay on Hands does NOT work, the cooldown is triggered, Tsulong will gain Forbearance, but no healing will be done.
- Effects like Guardian Spirit and Life Cocoon DO work.
- The raid still takes damage and WILL need healing.
- Tank damage from the melee attacks of the Embodied Terrors and Fright Spawns, as well as very high tank damage from the frontal cone attacks of the Fright Spawns.
- Healers must be prepared to dispel the following three effects during this phase:
- the Terrorize debuff from Tsulong;
- the Terrorize debuff from random raid members;
- the fear effect caused by Fright, from tanks or any other raid members hit by this cone attack.