Overview The Val'kyr Twins is a very straight-forward fight if you can follow a couple of (sometimes confusing) directions. You should start the fight by positioning the Twins next to the portals they are close to. This will allow you to switch "polarities" quickly when needed. Your raid, split in half, will need to be of color opposite of the Twin that half is closer to. So Fjola will have people with Dark Essence around her, and Eydis - with Light. After this initial preparation, you are set for the majority of the fight. The twist comes when it is time for the Val'kyr to execute a special ability - Twin Pact+Shield combo, or a Vortex. The first option is essentially a 20% heal, unless you break the shield and interrupt it; the second one is ~20k raid-wide damage, unless you have the right essence. The trick is to know when to react, and how to react. During a Pact+Shield combo, all the DPS will need to be of the color opposite of the Val'kyr that's casting - and they will, of course, need to switch and DPS her. So if the other Val'kyr (i.e. the one you are not DPSing normally) casts Pact+Shield, and you are DPS, you need to switch essence (by clicking the portal next to your Val'kyr) and switch to the other one. Don't forget to interrupt, and don't forget to switch color again as you go back to your normal Val'kyr. Avoiding the Vortexes is even easier, but tanks and healers will need to worry about those as well. If your Val'kyr casts Vortex, everybody on that side will need to switch color and wait for both the cast and the pulse to stop. You can and should use the time to run back to the portal with your original color (or DPS the other Val'kyr for a few seconds). After the AoE pulse is over with, switch color back and proceed normally. Abilities Light & Darkness - Absorbs Dark damage, reduces damage done against Dark targets, and increases damage done against Light targets. Absorbing Dark damage can proc Surge of Speed. Gained by clicking a Dark Essence. - Absorbs Light damage, reduces damage done against Light targets, and increases damage done against Dark targets. Absorbing Light damage can proc Surge of Speed. Gained by clicking a Light Essence. - Increases movement speed by 70% for 10 seconds. Concentrated Light/Darkness - Floats around the room. When a player or NPC of the same Essence absorbs it, they gain Powering Up. When a player or NPC of the opposite essence absorbs it, they take damage. - Causes Empowered Darkness or Empowered Light at 100 stacks. - Increases damage done against Light targets by 100%. Restores 20% of the target's maximum mana. Lasts 20 seconds. - Increases damage done against Dark targets by 100%. Restores 20% of the target's maximum mana. Lasts 15 seconds. - Inflicts 7,800 to 8,200 (25-Players: 8,775 to 9,225) Dark damage to enemies within 6 yards. Used whenever a Light player touches Concentrated Darkness. - Inflicts 7,800 to 8,200 (25-Players: 8,775 to 9,225) Light damage to enemies within 6 yards. Used whenever a Dark player touches Concentrated Light. Fjola Lightbane Light Essence - Fjola Lightbane is a Light creature. She takes less damage from targets with Light Essence and more damage from targets with Dark Essence. Her Vortex does Light damage. - Inflicts 100% weapon damage and increases all damage taken by the target by 20%. Each hit depletes a charge from the damage debuff. Lasts for 15 seconds or 10 charges. - Inflicts 1,500 (25-Players: 2,500) Light damage to the Dark enemies every 2 seconds. - Absorbs 175,000 (25-Players: 700,000) damage and prevents spell interruption. Lasts 15 seconds. Cast immediately before Twin's Pact. - Heals the Twin Val'kyr for 50% of their total health. Cast immediately after Shield of Lights. The 15-second cast can be interrupted if the shield is down. - Increases Physical damage done and hit chance by 20%. Increases attack speed by 10% per application of Val'kyr Quickness as well. Lasts 15 seconds. Used when Eydis is casting Twin Pact. - Inflicts 5,850 to 6,150 (25-Players: 8,775 to 9,225) Light damage every 1 second for 5 seconds. Channeled after 8-seconds cast. Affects only targets with Dark Essence. Eydis Darkbane Dark Essence - Eydis Darkbane is a Dark creature. She takes less damage from targets with Dark Essence and more damage from targets with Light Essence. Her Vortex does Dark damage. - Inflicts 100% weapon damage and increases all damage taken by the target by 20%. Each hit depletes a charge from the damage debuff. Lasts for 15 seconds or 10 charges. - Inflicts 1,500 (25-Players: 2,500) Dark damage to Light enemies every 2 seconds. - Absorbs 175,000 (25-Players: 700,000) damage and prevents spell interruption. Lasts 15 seconds. Cast immediately before Twin's Pact. - Heals the Twin Val'kyr for 50% of their total health. Cast immediately after Shield of Darkness. The 15-second cast can be interrupted if the shield is down. - Increases Physical damage done and hit chance by 20%. Increases attack speed by 10% per application of Val'kyr Quickness as well. Lasts 15 seconds. Used when Fjola is casting Twin Pact. - Inflicts 5,850 to 6,150 (25-Players: 9,263 to 9,737) Light damage every 1 second for 5 seconds. Channeled after 8-seconds cast. Affects only targets with Light Essence. Trial of the Grand Crusader For details about the specific differences in this fight on Heroic difficulty, check this blog.