The Obsidian Guard. Of the Warrior Clans the Obsidian Guard are an exclusively female clan made by the First Sons to serve as their personal guard sometimes gifted to the favored servants who currently have their good will or at least future malice. 

The Obsidian Guard feed on blood spilled in violence and are one of the few vampire clans that do not have fangs. The Obsidian Guard regenerate when caressed in the screams and suffering of the dying. The Obsidian Guard are blind to light only making out rough shapes, heat, blood, and magic. Obsidian Guard can command Wyverns. The Guard are almost invulnerable to all slashing and piercing attacks, only Obsidian and Steel that has never drawn blood before my pierce their skin. 

The Obsidian Guard burn in sunlight, can die from a single bite of a virgin steel blade, and burn at the touch of Obsidian. The Obsidian Guard are trained to be extremely Loyal and thus will attempt to follow orders even to their detriment.