Invasion of Theros // Ephara, Ever-Sheltering [March of the Machine] - 23

(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.) When Invasion of Theros enters the battlefield, search your library for an Aura, God, or Demigod card, reveal it, put it into your hand, then shuffle.