The Witchfire Trilogy
At the beginning of the trilogy, Magistrate Borloch sits on the city council and is second only to the mayor in power. He is a thoroughly evil man. He blackmailed the Corvis Coven into doing his bidding so his personal power would increase by their labors. When the Coven had outlived its usefulness to him, he had them executed. Borloch was himself manipulated into this by Vahn Oberen who had very specific reasons for wanting the Coven dead by his own hand.
By the middle of Shadow of the Exile, Borloch, Raelthorne, and Oberen have taken over Corvis. At this point, Borloch is nothing more than a puppet for Oberen and Raelthorne the Elder. At the beginning of the Legion of Lost Souls, with the death of the current mayor Borloch has taken over as the mayor of Corvis, but he is still in truth nothing more than Oberen’s pawn.