Ah thank you.

Yes, I'm thinking it may not kill the boss outright; but it may cripple his ability to play abilities(and wipe the board). Even if he shuffles his graveyard back into his deck it'll be greatly diminished.

I found Boundless Shadows for the priest, which if spammed in a long raid has the potential to remove the bosses entire ability deck from the game. Do you guys know if this is legal, or are bosses immune to this?