Roaring Furnace // Steaming Sauna

Two Rooms stapled to the same card, reading as opposite personalities that share one scaling axis: the number of cards in your hand. Roaring Furnace converts that count into targeted removal, damage to an opposing creature equal to how full your hand is, which means it wants your hand fat and does nothing when it's empty. Steaming Sauna is the setup for exactly that, stripping the maximum hand size and adding an end-step draw so the count only climbs. The split-door frame invites you to read them as a package, unlocking one early and holding the other until the hand is heavy, but nothing forces the pairing: the removal half is a clean standalone answer, the draw half a standalone engine. The timing wrinkle is the interesting part, and it cuts the other way from how these effects usually feel. Unlocking a door happens at sorcery speed, on your own turn, so you enter combat math with a known hand size. But the damage itself is a triggered ability that uses the stack, which means the count is not locked when you unlock the door; it is locked when the trigger resolves. Respond to your own trigger with an instant-speed draw and the Furnace fires larger than the board suggested. What the Room mechanic accomplishes here is letting a single card scale in two directions at once: hand size feeding a removal spell, and a removal spell rewarding the hand size the other half was built to inflate.