CURSED MIRROR This thing has had enough reprints now that basically any red deck can run it, and honestly
Golgari Grave-Troll and other dredge cards replace your draw with milling, letting you dump tons of cards into your graveyard
Token decks can also leverage infinite loops, like the one that comes from pairing Chatterfang, Squirrel General and Pitiless Plunderer
While Standard is definitely the format getting the most heat right now, I could easily see Modern getting some bans too
Despite that being the back of the card, the Vehicle sides are almost always cheaper, and the intended play pattern seems to be that you cast that half, fulfill some condition, and flip into the powerful Robot
Baneslayer Angel was a true tournament staple and, because of her Mythicness, commanded a massive price tag when she first saw print