Necronus, The Last Shadow

Deathtouch, Vigilance, Menace
When this card enters the battlefield, Exile each creature your opponent controls. You may cast
those cards from exile at any time, and spend
mana as though it was mana of any color to cast
them.
{3}{b}: Exile target creature
Remove 3 exiled creatures from the game: Return this card from your graveyard to the battlefield.
Remove 5 exiled creatures from the game:
Transform this card.