Belltower Sphinx

Most punishing blockers tax the act of attacking; this one taxes the act of dealing damage to it, regardless of where that damage originates. A 2/5 flyer is already awkward to push through: it brick-walls ground aggression and trades up against early fliers. The second ability turns the combat math punitive in the defender's favor. Block a 4/4, survive, and that creature's controller mills four. The trigger keys off the source's controller, which is the entire hinge of the card: the cost always lands on whoever owns the damage. An opponent's attacker or burn spell feeds their own graveyard, so swinging into or shocking the Sphinx advances a mill clock the attacker never asked for. That same orientation rules out the cute play: point your own removal or fight effect at the Sphinx and you mill yourself, because you control that source. The cost cannot be redirected across the table by your own action; the damage has to be coming from the other side for the penalty to land where you want it. So this is less a wall than a soft surcharge on aggression aimed at it, a body that asks the attacker whether grinding through five toughness is worth handing themselves an unscheduled detour through their library. Defensive stats and mill trigger pull in the same direction, and reading which player owns the next point of damage is the whole puzzle of playing it.