Death Knight:
Last Surprise effectiveness reduced by 35%
Magus of the Dead effectiveness reduced by 50%
Demon Hunter:
Revel in Pain effectiveness reduced by 50%
Revolving Blades effectiveness reduced by 35%
Thirsting Blades effectiveness reduced by 60%
Druid:
Streaking Stars damage reduced by 50%
Grove Tending effectiveness reduced by 25%
Raking Ferocity effectiveness reduced by 50%
Masterful Instincts effectiveness reduced by 50%
Lively Spirit effectiveness reduced by 50%
Arcanic Pulsar effectiveness reduced by 60%
Hunter:
Latent Poison effectiveness reduced by 30%
Dire Consequences effectiveness reduced by 50%
Surging Shots effectiveness reduced by 50%
Mage:
Arcane Pressure effectiveness reduced by 50%
Galvanizing Spark effectiveness reduced by 25%
Packed Ice effectiveness reduced by 50%
Intellect granted by Frigid Grasp is reduced by 66% when gained by casting Ice Form
Arcane Pummeling effectiveness reduced by 50%
Flash Freeze effectiveness reduced by 50%
Blaster Master effectiveness reduced by 50%
WildFire effectiveness reduced by 50%
Monk:
Glory of the Dawn effectiveness reduced by 50%
Paladin:
Avenger’s Might effectiveness reduced by 50%
Light’s Decree effectiveness reduced by 50%
Righteous Conviction effectiveness reduced by 50%
Priest:
Whispers of the Damned effectiveness reduced by 50%
Rogue:
Sharpened Blades effectiveness reduced by 65%
Deadshot effectiveness reduced by 45%
Fan of Blades effectiveness reduced by 75%
Snake Eyes is reduced by 30%
Nothing Personal effectiveness reduced by 50%
Shaman:
Surging Tides effectiveness reduced by 25%
Lava Shock effectiveness reduced by 60%
Pack Spirit is reduced by 80%
Roiling Storm only stacks once
Warlock:
Dreadful Calling effectiveness reduced by 50%
Baleful Invocation effectiveness reduced by 50%
Warrior:
Test of Might effectiveness reduced by 30%
Lord of War effectiveness reduced by 55%
Executioner’s Precision effectiveness reduced by 35%
Intimidating Presence effectiveness reduced by 50%
Crushing Assault effectiveness reduced by 50%
Bastion of Might effectiveness reduced by 50%
Gathering Storm effectiveness reduced by 35%
Neutral:
Azerite Veins healing reduced by 33%
I’m most likely missing some if people care to let me know I’ll update the list.