Nekros, Shadow of the Past

When Nekros, Shadow of the Past enters the battlefield, create X 2/2 Black Shadow creature tokens where X is the number of creature cards in your graveyard.
Sacrifice a Shadow. Nekros, Shadow of the Past gains indestructible until end of turn.
{t}: Exile target creature. Create a 2/2 Black Shadow creature token.
To a race that had forgotten to fear death, the Tenno proved a painful reminder.