The Executioner (TMS-084) [The Moonlit Savior]

[Stealth] You control a darkness magic stone and a resonator was put into your opponent's field this turn. (While this card is in your chant-standby area, you may play it without paying its cost when its [Stealth] condition is meet.) When this card enters your field from a chant-standby area, destroy target resonator with total cost 3 or less.