Vannifar, Evolved Enigma (Murders at Karlov Manor)

Legendary Creature — Elf Ooze Wizard - At the beginning of combat on your turn, choose one —
• Cloak a card from your hand. (Put it onto the battlefield face down as a 2/2 creature with ward {2}. Turn it face up any time for its mana cost if it's a creature card.)
• Put a +1/+1 counter on each colorless creature you control.