Minas Morgul, Dark Fortress

Minas Morgul, Dark Fortress
enters the battlefield tapped.
{t}: Add {b}.
{3}{b}, {t}: Put a shadow counter on target creature.
For as long as that creature has a shadow counter
on it, it's a Wraith in addition to its other types.
(A creature with shadow can block or be blocked
by only creatures with shadow.)