Fellowship of St. Giles

A relatively new player on the supernatural scene, the Fellowship of St. Giles (named for the patron saint of cripples) is made up of people who have been infected by Red Court vampires, but have yet to drink the lifeblood of another human to complete their transformation. The Fellowship helps its members control their urges, support each other, and fight the vampires who infected them. They are allied with the White Council in the war against the Red Court, but have little communication with them. Despite their recent emergence on the playing field, a member of the Blackened Denarius recognized Susan as a member because of her markings.
They have mystic tattoos placed all over their bodies that both grant them more restraint and act as a warning when they expend too much strength and are in danger of losing control. Normally the tattoos are not visible, but as the person uses the abilities their partial transformation gives them they begin to change. They initially are black and seem to swirl on the skin. As the Fellowship member reaches the danger zone, the tattoos turn red.
Being a half-vampire grants great potential strength, speed, and the ability to recover from incredible injury if they drink blood. Drawing on these powers creates massive amounts of bloodlust which is increasingly difficult to control.
Due to the events in Changes, the Fellowship is essentially defunct. The half-vampires have been cured (those not slain by Red Court treachery), and the Red Court has been destroyed. -Wikipedia