Right of Conscription

Search your library for a Grey Warden creature
and add it to your hand.
If you pay an additional {w}{b}, instead, take
control of target creature an opponent controls
with a Power less than 4
Should they need to, the Grey Wardens possess the
Right of Conscription, an authority that dates back to
the end of the First Blight and was given to them to
ensure they will always have enough members.