Nightfall
Nightfall is a Warlock spell in the WoW Forever client.
Gives your Corruption, Drain Soul, Drain Life, and Wrack spells a 2% chance to cause you to enter a Shadow Trance after damaging the opponent. The Shadow Trance reduces the casting time of your next Shadow Bolt spell by 100%.
Data from the WoW Forever client, build 1.60.1.70862, extracted .