Oath of Dravos

When Oath of Dravos enters the battlefield, each opponent loses life equal to the number of creature cards in your graveyard.
At the beginning of your end step, if a Planeswalker entered the battlefield under your control this turn, return target creature or Planeswalker card from your graveyard to the top of your deck.
To protect and preserve, in whatever form it takes, the cycle of life and death, I'll keep watch.