Vyran, Guardian of Yawgmoth

{p/b}{t}, Vyran, Guardian of Yawgmoth gains stone
When Vyran, Guardian of Yawgmoth gains stone
it gains six -1/+1 counters and defender
Whenever a creature attacks you or a plainswalker you
control Vyran, Guardian of Yawgmoth loses stone
When Vyran, Guardian of Yawgmoth loses stone destroy target attacking creature