Rank 2 is learned at level 26, causing it to refund 1 Soul Shard if the target dies while afflicted. This effect is capped at 1 soul shard per target; having more than one Unstable Affliction on the target will not refund additional soul shards.
Creeping Death - Causes Unstable Affliction to deal its damage 15% faster.
PvP Talents
Curse of Shadows - Causes each tick of Unstable Affliction to strike the target a second time for 20% of the damage while active.
[Endless Affliction] - Your Unstable Affliction deals the same damage as normal, but its duration is increased by 6 seconds.
[Rot and Decay] - Each time Drain Life deals damage it increases the remaining duration of Unstable Affliction your target by 1 second.
Azerite Traits
[Cascading Calamity] - Casting Unstable Affliction on a target afflicted by your Unstable Affliction increases your Haste for 15 seconds.
[Dreadful Calling] - Increases the damage dealt by Unstable Affliction and each successful cast reduces the cooldown of [Summon Darkglare] by 1 second.
Certain abilities that "remove" harmful effects rather than "dispelling" them, such as a rogue's [Cloak of Shadows] or a mage's [Ice Block], can remove Unstable Affliction without triggering its secondary effects. The Felhunter's [Devour Magic] is considered a dispel effect, and so will trigger Unstable Affliction's effects.
The 10% damage taken effect does not stack with multiple instances of Unstable Affliction.
Tips and tactics
This is a great spell for warlocks in arena. With all the curses a warlock has, a priest will be forced to dispel, which results in the direct damage.
In PvE, this spell is just another DoT. Most raid bosses do not dispel, and therefore the damage and silence of effects of dispelling this spell are wasted.
In PvP, it can help prevent your DoTs from being dispelled safely, as its secondary effects can cause significant damage to the dispeller.
The Warlock may now afflict a target with up to 5 Unstable Afflictions at once.
Now learned at level 14 (was 10).
Damage increased by 5%.
Hotfix (2016-09-23):Unstable Affliction damage increased by 15%.
Hotfix (2016-08-11):When Unstable Affliction is dispelled, it now deals 120% of the remaining spell damage (was 200%).
Patch 7.0.3 (2016-07-19): Redesigned. Damage per tick increased by 138%, duration reduced to 8 seconds (down from 14). Damage when dispelled is now affected by remaining duration. Now cost a Soul Shard instead of mana.
Patch 6.2.2 (2015-09-01): Now deals 10% less damage in PvP combat.
Patch 6.2.0 (2015-06-23): Now deals 12% more damage.
Hotfix (2014-12-15):Unstable Affliction's damage has been increased by 20%.
Patch 5.4.0 (2013-09-10): Damage has been increased by 21%.
Patch 5.2.0 (2013-03-05): Unstable Affliction's Backlash effect is now always a critical hit and deals approximately 15% more damage.
Patch 5.0.4 (2012-08-28): Now an Affliction specialization ability available at level 10. Duration reduced from 15 to 14 sec. No longer limited to one target.
Patch 4.1.0 (2011-04-26): Damage done when it is dispelled has been doubled, but this damage can no longer be critical. Damage dealt by Unstable Affliction when it is dispelled now properly benefits from [Shadow Mastery].
Patch 4.0.6 (2011-02-08): Silence effect has been reduced to 4 seconds, down from 5.
Patch 4.0.1 (2010-10-12): Now a primary spell in the Affliction tree.
Patch 3.3.0 (2009-12-08): The feedback damage from when this spell is dispelled is now affected by resilience as intended. Tooltip clarified to state that this spell is exclusive with Immolate.
Patch 3.2.0 (2009-08-04):[Immolate] and Unstable Affliction: All ranks of these two spells will now overwrite each other.
Patch 3.1.0 (2009-04-14): Feedback damage from dispelling this debuff will no longer be modified by effects on the victim which modify the damage the victim does.
Patch 3.0.8 (2009-01-20): Will now gain the correct damage modifiers for the creature type of the target.
Patch 3.0.2 (2008-10-14): Silence effect reduced to 3 seconds, down from 5.
Patch 2.3.0 (2007-11-13): The silence from this ability is now subject to diminishing returns.
Patch 2.2.0 (2007-09-25): This spell will no longer fail when a Warlock deselects their target midway through the cast.
Patch 2.0.3 (2007-01-09): The feedback from dispelling Unstable Affliction is now affected by [Shadow Mastery].
[Cascading Calamity], Creeping Death, Curse of Shadows, 
[Dreadful Calling], 
[Endless Affliction], 
[Mastery: Potent Afflictions], 
[Rot and Decay]
[Rot and Decay] - Each time Drain Life deals damage it increases the remaining duration of Unstable Affliction your target by 1 second.
