When tanking mobs with your Voidwalker, save casting Immolate until the end of your DoT rotation. Not only does it have the shortest duration, but as it deals initial damage, it generates the most threat and could possibly pull the mob to you.
Patch changes
Hotfix (2023-01-09):Damage increased by 10%. Does not apply to PvP.
Patch 10.0.0 (2022-10-25): Now learned at level 10 (was 11).
Patch 9.2.5a (2022-08-02): Damage increased by 20%.
Patch 9.0.1 (2020-10-13): Now learned at level 11 (was 10).
Immolate's periodic damage has a 50% chance to generate 1 Soul Shard Fragment (was a 15% chance to generate 1 Soul Shard).
Immolate's periodic damage critical strikes have a 100% chance to generate 1 Soul Shard Fragment (was a 30% chance to generate 1 Soul Shard).
Hotfix (2016-09-23):Immolate damage increased by 11%.
Hotfix (2016-08-16):Immolate no longer has a chance to generate a shard on its direct damage.
Patch 7.0.3 (2016-07-19): Now has a 15% chance to generate a Soul Shard (double on critical strikes). Direct damage increased by 162%, damage over time increased by 42%, and duration increased to 18 sec (was 15). Now learned at level 10 (was 12).
Hotfix (2014-12-15):Immolate's damage has been increased by 8%.
Hotfix (2014-10-30):Resolved a situation where interactions between Immolate, [Fire and Brimstone], and [Cataclysm] could cause Immolate to deal less damage than intended.
Hotfix (2013-09-23):Immolate's damage has been increased by 30%.
Patch 5.4.0 (2013-09-10): Damage has been increased by 10%.
Hotfix (2013-04-18):Fixed an issue where targets of Havoc were receiving more damage than intended from Immolate.
Patch 5.2.0 (2013-03-05): Now deals 15% more damage.
Patch 5.0.4 (2012-08-28): Now a level 12 Destruction specialization ability (was a level 3 ability for all warlocks) and replaces [Corruption]. Cooldown reduced from 2 sec to 1.5 sec.
Patch 4.0.3a (2010-11-23): Damage has been reduced by approximately 12%.
Patch 4.0.1 (2010-10-12): Only one Immolate per Warlock can be active on any one target. Mana cost 8% (was 17%) and has a range of 40 yd (was 30). Now learned at level 3 (was 1).
Patch 3.3.3 (2010-03-23): The damage-over-time component of this spell can now produce critical strikes.
Hotfix (2009-04-15):We have hotfixed the damage of the Warlock spell Conflagrate from 100% to 70% of Immolate's total periodic damage instantly. The tooltip may still show 100% until a future update though.
[Immolate].
[Flashpoint], 
[Scalding Flames], 
[Socrethar's Guile]
Hotfix (2023-01-09): Damage increased by 10%. Does not apply to PvP. 
Patch 9.2.5a (2022-08-02): Damage increased by 20%. 
Hotfix (2018-09-24): Damage increased by 10%. 
Hotfix (2017-07-27): Immolate's Soul Shard generation should now function as intended and match the tooltip. 
Hotfix (2015-07-20): Damage increased by 5%. 
[Fire and Brimstone], and 
[Cataclysm] could cause Immolate to deal less damage than intended. 
Hotfix (2013-09-23): Immolate's damage has been increased by 30%. 
[Corruption]. Cooldown reduced from 2 sec to 1.5 sec. 
Patch 4.0.3a (2010-11-23): Damage has been reduced by approximately 12%. 
Patch 3.3.3 (2010-03-23): The damage-over-time component of this spell can now produce critical strikes. 
[Unstable Affliction] will now overwrite each other. 
Patch 0.11 (2004-09-29): Duration, damage, and mana cost reduced. Deals damage faster. 
