Question from a reader: Lady Vengeance is always fighting demons, but she never kills them–just sends them away, usually with promises to return and avenge themselves. 

Why do the demons always get away?

Mechanically:

1) Because demons are really hard to banish, much less actually kill. All but impossible, really.

But really:

2) The demons are a metaphor for Lady V’s past traumas, continually coming back to haunt her. At best, we can push our pain and mistakes and regret away for a while, but they’re always there–always coming back to haunt us. 

Baggage we can’t leave behind.

Check out the story in question: “Baggage,” in the https://www.amazon.com/Shadowed-Souls-Jim-Butcher/dp/0451474996