Dawn, Moon's Guardian

Flying

Whenever Dawn deals combat damage to a player, you may pay {2}{u}. If you do, exile the top card of your library face down. You may look at that card
for as long as it remains exiled. You may play that card without paying its mana cost for as long as
Dawn remains on the battlefield.

"I and my sister protect the moon, the stars, and the universe beyond, it is because of our efforts that your worlds are kept safe..."