Forgotten Waters

When this Forgotten Waters is on the field it stays
on the field nothing can change that
(It can be sent to the hand of the owner)
On each players turn they must choose 4
cards in the grave add them to their
hand then exile them after the turn
even if they were used. If they can't
do it or the don't want to, they must pay 4 life.
"nettogroF nettogroF nettogroF"