Runic Corruption is a passive Unholy death knight ability.
Patch changes[]
Patch 10.0.0 (2022-10-25): Now learned at level 11 (was 21).
Patch 9.0.1 (2020-10-13): Proc chance increaed to 1.6% per Runic Power spent (was 1.4%). Now learned at level 21 (was 55).
Patch 8.0.1 (2018-07-17): Proc chance increaed to 1.4% per Runic Power spent (was 1%).
Patch 7.1.5 (2017-01-10): Now has a 1% chance to proc per Runic Power spent (was a 1.25% chance).
Patch 7.0.3 (2016-07-19): Now a passive ability available only to Unholy death knights. Chance per Runic Power reduced from 1.5% to 1.25%.
Hotfix (2014-10-14):Blood Tap, Runic Corruption, and Runic Empowerment should no longer incorrectly trigger when attempting to cast Death Coil against an invalid target.
Now procs with a 1.5% chance per Runic Power spent instead of 45% from Death Coil, Frost Strike, or Rune Strike.
Now a level 60 talent (down from level 75).
Hotfix (2013-09-24):Runic Corruption activating multiple times should no longer cause the ability to extend its duration by an incorrect amount.
Patch 5.4.0 (2013-09-10): Fixed a bug that caused [Improved Blood Presence] and Runic Corruption to incorrectly increase activation rates of some trinkets and effects.
Patch 5.0.4 (2012-08-28): Redesigned as a level 60 talent (was a Tier 3 Unholy talent). When you land a damaging [Death Coil], [Frost Strike], or [Rune Strike], your rune generation rate is increased by 100% for 3 sec.
Old: Reduces the cost of your Death Coil by 3/6, and causes your Runic Empowerment ability to no longer refresh a depleted rune, but instead to increase your rune regeneration rate by 50/100% for 3 sec.
Patch 4.0.6 (2011-02-08): Runic Corruption procs while the aura is already active now add 3 seconds to the existing aura duration, instead of simply refreshing/overwriting the existing aura.
[Runic Mastery]
Patch 10.0.0 (2022-10-25): Now learned at level 11 (was 21). 
[Improved Blood Presence] and Runic Corruption to incorrectly increase activation rates of some trinkets and effects. 
[Death Coil], 
