The Demon Spirit

The Demon trilogy by R.A. Salvatore began with The Demon Awakens and continues with The Demon Spirit. Corona is a fantasy world regularly menaced by the "demon dactyl" who organizes the usual suspects--goblins, dwarfs, giants--in hope of wiping out humanity. Having been comprehensively blown up in book one, the now bodiless demon resorts to corrupting the soul of the abbot who is Corona's chief religious leader. It's an easy task, since despite a few good monks the church is already a murderous, hypocritical outfit.