You can find the Shadow Labyrinth dungeon within Terokkar Forest, Outland.
The coordinates are (39.5,68.2)
1. Ambassador Hellmaw
/i Causes players to flee in fear. Corrosive Acid hits all players in front inflicting nature damage & reducing armor.
2. Blackheart the Inciter
/i Incite Chaos forces players to attack each other for 30 sec. War Stomp causes players to take damage & be knocked back. Charges at a player inflicting damage & stunning.
3. Grandmaster Vorpil
/i Teleports players to his platform & casts Rain of Fire, run away. Kill Void Travelers, if reach boss they explode causing wide damage & heal boss.
Heroic Differences: Banish stops a player from doing anything for 8 sec.
/i Sonic Boom hits players & reduces movement speed. Pulls all forward with Magnetic Pull. Stay away from player with Murmur’s Touch. 1 player must stay within melee range of boss otherwise Resonance deals heavy damage to all.
Heroic Differences: No Magnetic Pull in heroic. Sonic Shock deals arcane damage to current target. Thundering Storm throws bolts at any players further than 25 yards dealing nature damage.