Once every 5,000 years or so, a warrior cornugon devil is elevated by the powers of Hell. He undergoes a painful metamorphosis and becomes a unique creature—a malebranche. These fiends are only ever transformed for a single reason: to lead the infernal legions in conquest of an entire world or even a planar realm. Although malebranche are chosen to lead Hell's invasions, they do not always choose to achieve their victories through naked military might. Many of these devils are devious manipulators, who seek to corrupt a realm's defenders before unleashing their forces.