Barinthus is one of the Queen's Ravens and a former god, Manannan Mac Lir, a sea and weather god from Irish mythology. He is one of the most powerful beings within the Unseelie court. Andais extracted an oath from him that he would never take the throne before she allowed him entry.
Barinthus is feared in the courts, and whispers of his last duel still circulate, when a sidhe drowned in a summer meadow miles from any water. He never fought a duel unless it was to the death, anything else was a waste of his time.
He is self-conscious of the webbing between his fingers since a reporter in the 1950's referred to him as "the fish man." The reporter eventually drowned in a freak boating accident.
He is described as almost seven feet tall, 'as befit a god,' and possessing a nictating membrane over his eyes. When she was a child, he taught Merry to swim, and she thought wonderful that he could blink twice with each eye.
When Merry returned to Los Angeles, Barinthus stays behind at court to help build alliances for her.