Deep-Cavern Bat

Hand disruption used to be sorcery-speed and single-shot: Thoughtseize takes the card and hands you the information, but the exchange is a one-time transaction. What this bat does differently is stitch the disruption to a permanent, so the exiled card lives in limbo tied to a body on the battlefield. Kill the bat and the card comes back; that reversibility is the whole tension of the design. The disruption is only as durable as a 1/1, which means the card you take is a hostage rather than a prisoner, and any removal spell your opponent draws is also a rescue mission. What tips it from a fair trade into a repeatable menace is the pairing of that theft with evasion and lifegain on the same two-drop: it swings through the air for one, gains you a life, and keeps the stolen card locked away as long as it stays alive. Aggressive black decks get an early clock, a life buffer against mirror-race pressure, and information plus disruption all folded into one attacker, which is a lot of jobs for a body this small. The design lineage runs through Tidehollow Sculler and Kitesail Freebooter, both of which married a creature to a temporary exile clause; this one is the tightest version, adding flying and lifelink without inflating the cost. It is hand disruption that also has to be answered as a threat, and that dual-purpose demand is what makes it punch through resistance the earlier versions couldn't.