It is somewhat tough to say whether Zul'jin or Malacrass is the hardest 10-man boss in the game right now, but I believe Zul'jin is, for his fight requires the most coordination and spot-on execution. Even t6 geared guilds wipe to him occasionally (like us... though we fight him with alts most of the time), so I'll provide a personalized strat for all those attempting him.
Zul'jin has 5 phases. He starts in his human phase, and when you take him down to 80%, he'll start his Bear phase. At 60%, he starts his Eagle phase, at 40%, he starts his Lynx phase, and at 20%, he starts his Dragonhawk phase. The difficulty ranking of these phases are as follows (most difficult to least).
1)Lynx
2)Eagle
3)Dragonhawk
4)Bear
5)Human
Note that he drops aggro completely after each phase.
Phase 1: Human form (100-80%)
Zul'jin's human form is rather simple, he has only 2 abilities besides his hard melee.
-Whirlwind: From time to time he'll start spinning in place and a countdown cast will start. When he finishes with this "cast," he'll cleave most melee for 6k damage. Since his hit box is pretty big, the melee dps should hit him from as far away as possible and then run out as soon as he starts this ability. Run back in afterward to dps.
-Grievous Throw: He'll occasionally throw a huge knife at a random target (possibly melee, and the knife is HUGE). It'll deal an initial 2-3k damage, and then continue to tick for 2.4k every 2s until the target is healed to 100% hp, similar to the boss in Slave Pens. It'll tick forever if the target never gets topped off, be warned.
AOE down the adds at the beginning of the pull, making sure that when you make the pull, everyone's inside the outer fence for a flame door spawns. Have your tank tank him at the bottom of the steps, and the ranged dps should spread out in a semi-circle around him. The melee should of course be behind him. All of his abilities in this phase are very weak, including his melee. As long as your melee dps watches out for his whirlwinds, it's as simple as a tank and spank to 80%.
Phase 2: Bear Form (80-60%)
At 80%, he'll run to the middle of the platform and change into a bear. The fight becomes somewhat simpler, but the danger level increases.
-Creeping Paralysis: On a set timer. He'll occasionally put this on everyone in the raid. It's a debuff that will deal 4.5k damage after 5 secs if it isn't dispelled off the target. The target will also be stunned for 4 seconds. If you have one or two priests in your group, simply have everyone stacked on top of each other and have the priests cast mass dispel. If no priests are available, have your other healers dispel themselves and the tank and leave the debuff on the dps.
-Overpower: Exactly the same as the warrior ability. It'll hit up to 6k on plate, and due to this and his increased melee hits, your tank will be taking spike damage. Make sure the tank is always topped off.
Like I've mentioned above, as soon as the phase starts, have everyone stack on top of each other for mass dispels. The melee shouldn't worry too much about this for they could easily live through it, but if possible (and without taking too much healing off the main tank) dispel everyone.
Phase 3: Eagle Form (60-40%)
The most annoying phase of the whole encounter. When he reaches 60% hp, he'll run to the middle of the platform and fly up into the air. There'll be no damage coming from Zul'jin himself at all in this whole phase. Instead, 4 tornadoes will spawn that moves around the platform.
-Tornadoes: These will CHASE after people and deal around 1k to anyone that's close enough. It'll also deal a knockback. Once they hit someone, the tornadoes usually go after someone else. Be warned that it is possible to have multiple tornadoes chasing the same target.
-Energy Storm: This is a debuff that Zul'jin puts on everyone once the phase starts. It cannot be dispelled by any means. Whenever someone casts a spell that uses mana, he/she will be dealt 1250 damage from the tornadoes (some hunter spells not included).
Everyone should be constantly moving around the platform to avoid the tornadoes. Due to the energy storm, any class with a dot should put it on Zul'jin right at the beginning of phase transition when Energy Storm hasn't been cast yet (locks could CoD around 70%). Use your biggest heals if possible to make every cast count. Prayer of Mending works wonders in this fight. DPS casters should also cast their biggest casts, but wanding should be a big chunk of their dps in this phase to save healer mana. Do not get cornered and do not stay on the stairs; these places negate the knockback ability of the tornadoes and might make you take multiple tornado hits in quick succession. As a bug, it is possible for someone to get knocked over the fire door. He/she cannot get back on the fight, so avoid this at all costs by staying away from the entrance.
Casters could trick the debuff into thinking that only one spell is cast if he/she follows up a cast with an instant cast (for example, a prayer of mending after a greater heal). He/she will only be hit once, but he/she will be able to squeeze in two casts.
Phase 4: Lynx Form (40-20%)
This is the most healing intensive phase of the fight. A lot of people will be taking a lot of damage at once, and very very quick heals are needed to negate his Claw Rage ability.
-Claw Rage: Occasionally Zul'jin will target a person at random, charge, and hit him/her 12 times in 6 seconds. The first hit deals 500, and the subsequent hits deal 150 more each hit (650, 800, 950, etc). This damage is not mitigated by armor, so the target will be dealt 16k damage in 6 seconds. This is a lot of damage, and if all the healers don't target the person being hit and spam heals on him/her, that person will die 100% of the time.
Lynx Hush: Occasionally he'll charge around your raid, dealing 2k on 9 targets and putting a debuff on them that ticks for 1.5k every 2s over 10s. Combined with the Claw Rage, there's a lot of healing that's needed to be done.
This phase is basically a test of your healers' skills. The debuffs that he puts up deal a decent amount of damage. While the debuff is ticking, Zul'jin charges at a target that MUST be healed very fast. There's no way to negate his attacks except with quick efficient heals. Having your ranged dps at max range helps too for it takes a while for him to reach a ranged.
Note that it is very easy to pull aggro in this phase but it must not happen. Your tank won't be tanking him a lot due to his 2 abilities, so watch your threat.
It is possible for the Claw Rage targeted player to vanish, ice block, bop, or divine shield out of it. Zul'jin will instead unleash the remaining Claw Rage on the person highest on aggro, hopefully your tank.
Phase 5: Dragonhawk Form (20-0%)
Essentially a tank an spank. This is a test to see if enough people survived the previous phases and is a dps race to the finish.
-Flame Whirl: He'll do this about every 12 seconds. It at first deals 1k damage to everyone, but with each whirl everyone will get a stacking debuff that increases flame damage taken.
-Flame Breath: A frontal cone attack that deals 2-3k fire damage.
-Fire Columns: He'll spawn this at random on top of people. They look like fluxing holy fires, and deals 900 damage per second to anyone standing in one.
Note that all of his fire abilities increase in damage over time due to the debuff that he puts on everyone.
Basically spread out, move out of the fire columns, and dps as hard as you can without pulling aggro. If enough people survive the previous phases, this phase will be very easy.
Zul'jin has 5 phases. He starts in his human phase, and when you take him down to 80%, he'll start his Bear phase. At 60%, he starts his Eagle phase, at 40%, he starts his Lynx phase, and at 20%, he starts his Dragonhawk phase. The difficulty ranking of these phases are as follows (most difficult to least).
1)Lynx
2)Eagle
3)Dragonhawk
4)Bear
5)Human
Note that he drops aggro completely after each phase.
Phase 1: Human form (100-80%)
Zul'jin's human form is rather simple, he has only 2 abilities besides his hard melee.
-Whirlwind: From time to time he'll start spinning in place and a countdown cast will start. When he finishes with this "cast," he'll cleave most melee for 6k damage. Since his hit box is pretty big, the melee dps should hit him from as far away as possible and then run out as soon as he starts this ability. Run back in afterward to dps.
-Grievous Throw: He'll occasionally throw a huge knife at a random target (possibly melee, and the knife is HUGE). It'll deal an initial 2-3k damage, and then continue to tick for 2.4k every 2s until the target is healed to 100% hp, similar to the boss in Slave Pens. It'll tick forever if the target never gets topped off, be warned.
AOE down the adds at the beginning of the pull, making sure that when you make the pull, everyone's inside the outer fence for a flame door spawns. Have your tank tank him at the bottom of the steps, and the ranged dps should spread out in a semi-circle around him. The melee should of course be behind him. All of his abilities in this phase are very weak, including his melee. As long as your melee dps watches out for his whirlwinds, it's as simple as a tank and spank to 80%.
Phase 2: Bear Form (80-60%)
At 80%, he'll run to the middle of the platform and change into a bear. The fight becomes somewhat simpler, but the danger level increases.
-Creeping Paralysis: On a set timer. He'll occasionally put this on everyone in the raid. It's a debuff that will deal 4.5k damage after 5 secs if it isn't dispelled off the target. The target will also be stunned for 4 seconds. If you have one or two priests in your group, simply have everyone stacked on top of each other and have the priests cast mass dispel. If no priests are available, have your other healers dispel themselves and the tank and leave the debuff on the dps.
-Overpower: Exactly the same as the warrior ability. It'll hit up to 6k on plate, and due to this and his increased melee hits, your tank will be taking spike damage. Make sure the tank is always topped off.
Like I've mentioned above, as soon as the phase starts, have everyone stack on top of each other for mass dispels. The melee shouldn't worry too much about this for they could easily live through it, but if possible (and without taking too much healing off the main tank) dispel everyone.
Phase 3: Eagle Form (60-40%)
The most annoying phase of the whole encounter. When he reaches 60% hp, he'll run to the middle of the platform and fly up into the air. There'll be no damage coming from Zul'jin himself at all in this whole phase. Instead, 4 tornadoes will spawn that moves around the platform.
-Tornadoes: These will CHASE after people and deal around 1k to anyone that's close enough. It'll also deal a knockback. Once they hit someone, the tornadoes usually go after someone else. Be warned that it is possible to have multiple tornadoes chasing the same target.
-Energy Storm: This is a debuff that Zul'jin puts on everyone once the phase starts. It cannot be dispelled by any means. Whenever someone casts a spell that uses mana, he/she will be dealt 1250 damage from the tornadoes (some hunter spells not included).
Everyone should be constantly moving around the platform to avoid the tornadoes. Due to the energy storm, any class with a dot should put it on Zul'jin right at the beginning of phase transition when Energy Storm hasn't been cast yet (locks could CoD around 70%). Use your biggest heals if possible to make every cast count. Prayer of Mending works wonders in this fight. DPS casters should also cast their biggest casts, but wanding should be a big chunk of their dps in this phase to save healer mana. Do not get cornered and do not stay on the stairs; these places negate the knockback ability of the tornadoes and might make you take multiple tornado hits in quick succession. As a bug, it is possible for someone to get knocked over the fire door. He/she cannot get back on the fight, so avoid this at all costs by staying away from the entrance.
Casters could trick the debuff into thinking that only one spell is cast if he/she follows up a cast with an instant cast (for example, a prayer of mending after a greater heal). He/she will only be hit once, but he/she will be able to squeeze in two casts.
Phase 4: Lynx Form (40-20%)
This is the most healing intensive phase of the fight. A lot of people will be taking a lot of damage at once, and very very quick heals are needed to negate his Claw Rage ability.
-Claw Rage: Occasionally Zul'jin will target a person at random, charge, and hit him/her 12 times in 6 seconds. The first hit deals 500, and the subsequent hits deal 150 more each hit (650, 800, 950, etc). This damage is not mitigated by armor, so the target will be dealt 16k damage in 6 seconds. This is a lot of damage, and if all the healers don't target the person being hit and spam heals on him/her, that person will die 100% of the time.
Lynx Hush: Occasionally he'll charge around your raid, dealing 2k on 9 targets and putting a debuff on them that ticks for 1.5k every 2s over 10s. Combined with the Claw Rage, there's a lot of healing that's needed to be done.
This phase is basically a test of your healers' skills. The debuffs that he puts up deal a decent amount of damage. While the debuff is ticking, Zul'jin charges at a target that MUST be healed very fast. There's no way to negate his attacks except with quick efficient heals. Having your ranged dps at max range helps too for it takes a while for him to reach a ranged.
Note that it is very easy to pull aggro in this phase but it must not happen. Your tank won't be tanking him a lot due to his 2 abilities, so watch your threat.
It is possible for the Claw Rage targeted player to vanish, ice block, bop, or divine shield out of it. Zul'jin will instead unleash the remaining Claw Rage on the person highest on aggro, hopefully your tank.
Phase 5: Dragonhawk Form (20-0%)
Essentially a tank an spank. This is a test to see if enough people survived the previous phases and is a dps race to the finish.
-Flame Whirl: He'll do this about every 12 seconds. It at first deals 1k damage to everyone, but with each whirl everyone will get a stacking debuff that increases flame damage taken.
-Flame Breath: A frontal cone attack that deals 2-3k fire damage.
-Fire Columns: He'll spawn this at random on top of people. They look like fluxing holy fires, and deals 900 damage per second to anyone standing in one.
Note that all of his fire abilities increase in damage over time due to the debuff that he puts on everyone.
Basically spread out, move out of the fire columns, and dps as hard as you can without pulling aggro. If enough people survive the previous phases, this phase will be very easy.