When fighting Anduin in Sepulcher of the First Ones, during the second intermission, if Anduin reaches 10% health and transitions to phase 3, the Force of Will damage reduction will expire and players will take full damage from a few ticks of Remorseless Winter.
https://www.warcraftlogs.com/reports/RkGwTXDtAc3CP2HL/#fight=21&type=deaths&death=5