Halion
Health: 11,156,000

/43,500,000

/15,339,900


/58,600,000

General abilities
Twilight Precision - Increases Halion's hit chance by 5% and decreases the raid's dodge chance by 20%.
Cleave and
Tail Swipe - Typical dragon abilities.
Physical Realm abilities
Flame Breath - Up to 22,500

/37,500

fire damage in a cone in front of Halion.
Meteor Strike - Cast at a random raider's feet and lands 5 seconds later. Causes up to 21,250 fire damage to everyone within 12 yards of where it lands, and shoots out fire in an X shape after it hits the ground.
Fiery Combustion - 4000 fire damage every 2 seconds for 30 seconds to a random raider, can be dispelled.
Mark of Combustion - A stack is gained by the affected player every time
Fiery Combustion ticks.
Combustion - Upon removal of
Fiery Combustion, knocks players back and inflicts up to Up to 3375

/4500

fire damage every second that the target remains in its explosion area. The explosion area begins at 6 yards, but increases in size for every
Mark of Combustion that was on that player, consuming the entire stack.
Twilight Realm abilities
Dark Breath - Up to 22,500

/37,500

shadow damage in a cone in front of Halion.
Dusk Shroud - Up to 3000

/4500

shadow damage every 2 seconds to everyone in the Twilight Realm.
Twilight Cutter - Cast by 2/4

shadow pulsars swirling outside of the fight's perimeter. A beam that does up to 16,125 shadow damage every second to players touched by the beam. Beam is channeled, lasts 10 seconds, and is cast once every 30 seconds.
Soul Consumption - 4000 shadow damage every 2 seconds for 30 seconds to a random raider, can be dispelled.
Mark of Consumption - A stack is gained by the affected player every time
Soul Consumption ticks.
Consumption - Upon removal of
Soul Consumption, pulls players in and inflicts up to Up to 3375

/4500

shadow damage every second that the target remains in its explosion area. The explosion area begins at 6 yards, but increases in size for every
Mark of Consumption that was on that player, consuming the entire stack.
Strategy
Halion is a 3-phase, 2-tank fight. The first phase takes place in the physical realm, while the second phase takes place in the twilight realm. Halion splits in the third phase, and you must fight him in both realms at once. Halion is a typical dragon with cleave, tail swipe, and breath that you don't want to get caught in.
Fiery Combustion / Soul Consumption
These two abilities are very similar and happen throughout the fight. One person gets hit with one of the debuffs
Fiery Combustion or
Soul Consumption, depending on the realm you are in at the time. That person must get away from the raid quickly, and then be cleansed. Players must then get out of the explosion area. For
Fiery Combustion, that's not hard because you get knocked back. However,
Soul Consumption pulls players in, so in the twilight realm everyone must be aware that when they get pulled in they must immediately run out.
Phase 1
In Phase 1, you must avoid
Meteor Strike and the cross of fire they create while dealing with
Fiery Combustion.
Phase 2
In Phase 2, the Twilight Cutters circling the outside will create beams called
Twilight Cutter that you should not stand in. Standing in them for longer than a second usually means death. Healers must AoE heal in the twilight realm due to the
Dark Shroud debuff.
By far the most difficult mechanic to deal with is the
Twilight Cutter beams. Keep all raiders to the right of the dragon, and the tank should keep Halion in the center of the room and rotate him accordingly while the beams are active. Once you deal with the first beam, the raid should get into a cycle that makes it easy to avoid the beams using this strategy.
You can keep the fire tank and a healer outside in this phase, there is no penalty for doing so.
Phase 3
In Phase 3, the raid must split up, with one tank in the physical realm and one tank in the twilight realm. Healers and DPS must also be assigned evenly. The fight goes very much like Phase 1 and 2, except Halion gains a debuff called
Corporeality, starting at 50%. As you DPS him, his corporeality shifts to the opposite realm. Try to keep the debuff at 50%. If the debuff moves from 50%, he starts doing and taking more damage in the realm he being shifted towards. At 20% or 80%, he is taking 50% and dealing 30% less damage in the realm he is being shifted away from, but taking 100% and dealing 60% more damage in the realm his is being shifted towards.
Depending on how well your tanks and healers are performing, you may be able to intentionally shift him towards one realm in order to increase the damage Halion takes. However, how far you take him is limited entirely by your tank's health, as 60,000 fire or shadow breath damage is a lot to take on 25-man at 20% or 80%.