I played the new adventures first chapter on heroic and managed to build a kinda consistent Milldeck I made it to the boss with.
But trying to mill him it happened on 2 occasions, that almost before I got him running out of cards, he just got 20 more cards added to his deck. I had not played any card adding cards to his deck, nor had his heropower or any permanent effect that was mentioned anywhere left a note on WHY he just got his deck stocked up. That's really frustrating, and so I want to ask here:
Why did the Plaguelord of "Tombs of terror"'s first chapter get aproximately 20 cards added to his deck multiple times, and what are these cards?