Frostveil Ambush 
Instant
Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.
Cycling 
(, Discard this card: Draw a card.)
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL