You can find the Seat of the Triumvirate dungeon entrance within Mac’Aree, Argus.
The coordinates are (22.2,56.2)
1. Zuraal the Ascended
Mythic Differences: Coalesced Void adds leave purple sludge on ground as they move towards boss. A random player is put into the void realm (boss casts Umbra Shift), fill bar by killing Dark Aberrations to press button. A player will also be fixated kite, kite boss around.
/i Tank keep threat on Boss & Darkfang. Avoid the traps on ground. Boss marks & dashes between players (Umbral Flanking), unmarked players avoid getting hit. Player attacked by Darkfangs ‘Ravaging Darkness’ move away.
Mythic Differences: Shadewing will be added to the fight (all 3 bosses do share a health pool). Tank keep threat on all 3. Interrupt ‘Dread Screech’ cast by Shadewing.
3. Viceroy Nezhar
Mythic Differences: Boss has an insanity bar, once reaches 100% he summons 2 Shadowguard Voidtenders, boss is immune until adds are killed. Must also interrupt ‘Eternal Twilight’.
/i Kill the Greater Rift Warden to close portal, avoid purple patches on ground & 1 player run to soak the bolt ‘Fragment of Dispair’ marked on the ground. When adds are killed & portals gone boss is attackable.
Mythic Differences: purple patches (Remnant of Anguish) will relocate to players location, players stack & move as a group.