26 EXPENSIVE: CRUSH CARD VIRUS ($2474)
While Modern and Legacy players are theoretically so invested in the game that they won't quit based on a banning (especially when the banning improves the format), if someone buys their first Standard deck and it's suddenly banned, it's very possible that these players will give up on the game altogether
(Sorry for that reminder!) Much like cycling, its name was chosen for a mechanical reason more than a flavorful one
As long as Knife and Death is on the stack, players can't cast spells, activate abilities, or move their permanents
However, I do not think that this engine benefits U.A
Though these sets aren't quite recent, they're not vintage either, so cards from the XY era tend to be forgotten