Sheriff of Thistlebury

Whenever Sheriff of Thistlebury attacks, tap
target creature an opponent controls.
{2}, Discard a card: Sheriff of Thistlebury
gets +1/+1 and vigilance until end of turn.
At the beginning of your end step, you may pay {x}. If you do, Sheriff of Thistlebury deals X
damage to target tapped creature an opponent controls.