Throne of Eldraine brought with it a bunch of interesting support cards for the mill archetype, which, when combined with some holdovers from last Standard like Drowned Secrets, give us the critical mass of mill cards necessary to make a (possibly?) competitive deck
This card weighs the heaviest on your bank account when it's found as a Step-and-Compleat Foil
Ruin-Lurker Bat One white, Creature - Bat - 1/1 - Uncommon Flying, lifelink At the beginning of your end step, if you descended this turn, scry 1
This means that the easiest way to shut her down is just to kill her, forcing you to pay more through commander tax each time you want to replay her or to run multiple protection options to keep her alive and kicking
8) Blow to the Head This is the name that I use whenever I can't come up with a good name for a black discard spell