Zarath

He is the pure embodiment of evil and chaos. He revels in chaos and suffering. Unlike other evil deities who have plans for world domination or destruction Zarath has no interest in this. What brings Zarath joy is simply murder, suffering, evil and chaos. And if something gives you pleasure why not do it, that is his philosophy.
The church of Zarath is outlawed in most civilized places and is hence often practiced in secret. Zarath has a large following amongst assassins though. And ofcourse amongst the more savage races also.
The holy symbol of Zarath varies from place to place and from worshipper to worshipper but it is often some depiction of a skull and blood but it can be anything really, though it has to convey some sort of chaotic evil intent.