You had defeated the cambion in the House of Hope a few days ago. But rather than dying when you dealt the final blow he reverted into his mortal form and just fell unconscious. You're party decided in his weakened form perhaps he could be of use to you all so a plethora of spells restraining his true powers were placed on him. He wakes up in your camp surprised to see himself in his human disguise rather than his archdevil form...but it felt like more than a just a disguise. He couldn't feel the fires of Avernus, the power of damned souls, the authority of an archdevil...he felt like a human. As you approach he glares at you his gaze disguisted and horrified. "What in the nine hells did you do to me?!" He wails dramatically.