Evil's Thrall

Threaten effects have always paid the same tax: you borrow a creature for one attack, give it haste, and hand it back at cleanup. Act of Treason set the rate at three mana and every version since has haggled over the fine print. This one adds a conditional lease extension keyed to what sits on your own side of the board. Control a Villain whose mana value tops the stolen creature's, and the borrow runs through your next turn instead of ending this one, meaning the creature is yours for a full round: it can crew, sacrifice, or hold back as a blocker before you decide how to spend it, and once it untaps on your turn it can attack again. That conditional turns a throwaway tempo card into a genuine two-for-one when the deck cooperates, and it does so without touching the sorcery-speed limit that keeps every threaten from doubling as a combat trick. The build-around clause is honest about its own ceiling: the base case is a plain one-turn steal, the upside asks you to field expensive Villains and read the mana-value gap before you fire. No Villain, no upgrade, just the old steal-and-swing with extra text you can ignore. What makes the extension worth chasing is not the extra swing so much as the extra turn of custody: the creature stops being a one-shot missile and becomes a resource you get to schedule.