Agent Regina was an assassin in the now-defunct Department of Culture, which apparently merged with the Department of Mary Sues, Phantom of the Opera Division. After her former partner attempted to kill Raoul and went insane (in that order), she recruited her friend Berou. The pair were written by Nemthenga, though Berou was based on an actual friend of hers called Berouge.
Regina is a Daroga fan and a former Suethor. She may or may not have training from FicPsych; she doubled as a counselor for her first partner before her partner ended up too insane to continue to function as an agent.