This item drops from Morchok, Warlord Zon'ozz, Yor'sahj the Unsleeping, Hagara the Stormbinder, Ultraxion and Warmaster Blackhorn in Dragon Soul.
Patches and hotfixes
- Hotfix (2015-10-06): "Dragon Soul trinkets should now correctly have a chance to trigger their effects when players are scaled down below level 90."
- Patch 4.3.2 (2012-01-31): Vial of Shadows damage (Lightning Strike) has been reduced to approximately one-third of previous damage. However, it will now trigger approximately 3 times as often. This is intended to keep overall DPS the same while reducing burst damage, especially in PvP.
- Hotfix (2011-12-13): "Some items have new/changed class restrictions (LFR Versions)."
- Patch 4.3.0 (2011-11-29): Added.