wotc
If a card in a player’s graveyard has {X} in its mana cost, X is considered to be 0.
If a card in a player’s graveyard has {X} in its mana cost, X is considered to be 0.
If you return no creature cards to the battlefield, you won’t put any counters on any creatures.
You could target a single creature card with Call of the Death-Dweller. In this case, you’ll put both counters on that creature.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Vincent Proce
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
If you return two creature cards, you may put one counter on each or put both counters on one.