The problem is Kingsbane.
When mill has a buffed kings (which is super easy) it is near unbeatable, and not at all hard to pilot.
step 1: Take your 12 damage lifestealing dagger and smash anything you feel like....
Step 2: wait for opponent to concede or keep smashing face till you kill them
Before Kings, Mill was a tough deck and required a lot of skill to play against, now it is just annoying and if they get lifesteal by turn 3-4 and start buffing, you lose.