Seriph, War Advisor

Seriph, War Advisor enters the battlefield with X bribery counters.
Creatures your opponents control cannot attack
you unless they pay {x}, where X is the number
of bribery counters on Seriph, War Advisor.
At the end of combat, if a creature dealt combat
damage to you or a creature you control, remove
a bribery counter from Seriph, War Advisor.