Nazh'Gor, Devourer's Echo

Nazh'Gor, Devourer's Echo's power is equal to
the ammount of non-land cards in all graveyards.
{3}: Target a non-land card from any graveyard.
Nazh'Gor becomes a copy of that card except its
name is Nazh'Gor, Devourer's Echo's, it's a legendary creature in addition to its other types,
and has this ability