Final-Sting Faerie

Removal that can only fire after the damage has already been dealt: the entry trigger demands a creature that was dealt damage this turn, which folds the whole card into a combat-math problem you have to set up before it ever hits the battlefield. The body and the trigger are sequenced, not simultaneous, so this is not a flier that swings and then executes. It is a finisher you drop after the rest of your board has done its work: an attacker chipped a blocker into the red, a burn spell left a creature one nick short, a fight or ping wounded something earlier in the turn. Only then does the destroy clause have a legal target. That damage prerequisite is the constraint paying for the rate: a four-mana 2/2 with evasion is forgettable, but bundling a kill spell behind a wound turns it into a tempo play that wants you already winning the combat, not reacting to a clean board. It rewards aggressive black decks that are constantly dealing incidental damage, and does nothing the turn nothing got hit. The Assassin typing reads as exactly the right flavor: this is murder that needs an existing wound to finish, not a bolt from nowhere. Blink and recursion are where the design opens up, since each re-entry is another post-combat execution, provided the board still shows fresh blood.