We know very little about Gerald. At his art exhibit he once offered to help Alphonse to create are for "All of eternity" (Diary of a Teenage Vampire) and tried to hold his gaze but Alphonse managed to avoid it. He came with several associates and when Alphonse tried to soulgaze with him later he was unable to do so.
Later on, an appointment was made to look at the sculptures on the University grounds where Alphonse had an art piece. They attack the vampires. Gerald tried to run away but was attacked by Bijoux. This attack gave him severe agoraphobia and he managed to escape. They never found out why the Red Court had decided to return at that time.