https://www.mmo-champion.com/content/7206-Varimathras-Guide-WoW-Antorus-the-Burning-Boss-Strategies-and-Loot-ListOverview
Varimathras is the single target Patchwerk style fight of the raid zone. This boss has few abilities, making most of his difficulty the tight damage check before he enrages.
Heroic Changes
Torment of Frost fills the encounter area with ice, reducing movement speed and dealing frost damage to the raid.
Torment of Fel fills the encounter area with fel flames, dealing increasing periodic damage to the raid.
Necrotic Embrace will mark a target, which upon expiration will deal Shadow damage and spread to all players within a 10 yard radius.
Heroic specific mechanics and abilities will be marked with [Heroic] throughout the guide.
Strategy and Positioning
Two markers should be placed on the back-left, and back-right side of the boss.
The entire raid, except the tanks, should start on one of the markers, and move to the other one when Dark Fissures appear.
Rogues should stand closer to the boss to intercept Marked Prey, because they can easily Shadowstep back.
Never stand in front of the boss if you are a non-tank class.
Strategies by Role
Hopefully these strategies and tips in our Varimathras guide will help you to defeat this encounter!
All Roles
Taking any shadow damage will trigger Misery, reducing all healing taken by 100%, and increasing all Physical damage taken by 200% for 7 seconds.
Quickly move to the opposite marker when Dark Fissures appear.
[Heroic] Move at least 10 yards away from the raid if affected by Necrotic Embrace.
[Heroic] Use raidwide movement increasing abilities during Torment of Frost transitions.
DPS
Kill the boss before he transitions to Torment of Shadow.
Healers
[Heroic] Players affected by Necrotic Embrace should be at full health before their debuff expires.
The main tank will take a large burst of damage whenever the boss reaches full energy.
[Heroic] The raid will take increasing damage during Torment of Fel, making healing cooldowns very effective to use during this part of the encounter.
Tanks
The main tank should stand in front of the boss, as close to him as possible, while the off-tank should stand behind the boss within 8 yards of the main tank.
Tanks should taunt swap after each cast of Shadow Strike, which occurs every time the boss reaches full energy.
The boss should always be tanked facing away from the raid.