Invasion of Amonkhet

<i>(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)</i>

When Invasion of Amonkhet enters the battlefield, each player mills three cards, then each opponent discards a card and you draw a card. <i>(To mill three cards, a player puts the top three cards of their library into their graveyard.)</i>