Evil Brand( Exemplars of Evil, p. 24)
You are physically marked forever as the servant of an evil power greater than yourself. The symbol is unquestionable in its perversity, depicting a depravity so unthinkable that all who see it know beyond a doubt that you serve an evil patron.
Evil creatures automatically recognize the symbol now emblazoned upon you as a sign of your utter depravity and your discipleship to a powerful creature of evil, although the brand does not necessarily reveal your patron's identity. You gain a +2 circumstance bonus on Diplomacy and Intimidate checks made against evil creatures.