Vrontioss, the Sentinel

Flying, Hexproof, Can block any number of creatures
When Vrontioss enters the battlefield its controller and all creatures they control have Hexproof until the start of your next turn.
{g}{u}{w}{b}, {t}: your creatures gain +1/+1 and Hexproof until the end of the turn, and target player's creatures get -1/-1 and don't untap during their next untap step.