Atraxa, Void Unifier

Trample, vigilance, flying, infect

When Atraxa, Void Unifier enters the battlefield, exile the
top ten cards of your library. For each card type among
cards exiled this way, you may cast a card of that type from
among them without paying its mana cost. If a card would
be put into the graveyard from anywhere, exile it instead.

Whenever Atraxa, Void Unifier attacks, Exile target
permanent defending player controls and proliferate twice.