Flash When Station Seven Host enters, if you cast it, copy target instant or sorcery spell you control. You may choose new targets for the copy. Undercover
This spell costs {2} less to cast if you've disturbed the peace this turn. Exile the top three cards of your library. Until the end of your next turn, you may play those cards.
First strike Players can't gain life. Whenever a player casts a spell from a graveyard or exile or activates an ability of a card in a graveyard or exile, Vigilante Firebug deals 2 damage to that player.
Exile the top X cards of your library. When you do, choose one — • Until the end of your next turn, you may play cards exiled this way. • Villain's Gambit deals damage to any target equal to the number of cards exiled by Villain's Gambit.
Whenever a face-down creature you control deals combat damage to an opponent, you may exile it, then cast it without paying its mana cost. {2}{R}{R}: Put a card from your hand onto the battlefield face down.
When Alluring Spirit enters, put a +1/+1 counter on target face-down creature you control. Each face-down creature you control enters with an additional +1/+1 counter on it.
Look at the top four cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
“Invisible ink? Go fetch the good stuff.” —Abigail, to a Cawyer recruit
Target creature gets +5/+5, gains trample, and becomes a Horror in addition to its other creature types until end of turn. It can't be blocked by more than one creature this turn.
Everyone has their inner monsters. Some are just more literal than others.
Whenever one or more creatures you control deal combat damage to an opponent, investigate. Whenever you sacrifice a Clue, put a +1/+1 counter on target creature.