Kefnet's Monument (AKH) from Amonkhet, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Titus Lunter
• Card Text:
  Blue creature spells you cast cost 1 less to cast.
  Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.