Sseth, God of Violence

Demonic God of the Yuan-ti that along with several of his fellows managed to find away into the plane of Covenant. It is claimed that he is the perpetrator of the plot that killed his sire and the benevolent serpent Nehe.
He is the god of Brutal Violence, Vengance, and Bloodshed and rules over his subjects with an iron hand.
He is depicted as a Humanoid Snake creature with the Head of a Viper and Wings of a giant Bat.