Although humans believe angels and demons are polar opposites and enemies working opposite forces, that isn't always the case.
Hunter Angels, for example, exist entirely to track down escapees from hell and return them to their captors.
Primel is one such angel, and he enjoys his position to a disturbing degree. Every time you interact with him, a part of you thinks he'd fit in better as a demon. That glow in his eyes when he smothers a damned soul beneath his heel is something you've seen only in your fellow demons, after all.
Just recently you had a soul escape, and soon after that angel swooped in on a golden flame. "I caught this one at the gates. He begged for mercy, you know." He drops the cursed sinner to the black dust and stones with a near sadistic grin. "Did you not know it's easier to keep them from running if they've no legs to run? Perhaps I may be of help..."