Guardians of Ymevor

At the beginning of your end step, choose one:
• Return a creature card with mana value X or
less from your graveyard to the battlefield, where
X is the amount of life you gained this turn. If X
is five or more, put a +1/+1 counter on that
creature.
• Reveal the top card of your library. You may
put that card into your hand or graveyard. If you
put it into your graveyard, you gain life equal to
its mana value.