In Ny’alotha Normal when fighting N’Zoth the Corruptor, you’re not supposed to get debuffed with Fettered Mind in Normal when going into his ‘Deathwing vision’, it’s only an Heroic/Mythic thing.
The ability isn’t even in the Encounter Journal in Normal.
This makes N’Zoth unsoloable in NM.
Just two weeks ago, I was able to solo him, and I suspect that when Blizz made a change to make the legendary cloak optional, someone must’ve accidentally copied the spell from Heroic to Normal thinking they were fixing a bug, I dunno…