Kalista Story/Personality Questions

Sadly one of the few non-ragey Kalista threads recently, but I just had a few questions I hoped someone would/could give their input on despite it being after her AMA. Anyway I'm thinking Kalista is/could be a cool character to write about, but I was curious as to if any of the story people or CertainlyT himself would answer a few questions.

Kalista seems to have mostly lost her original self to the numerous amounts souls she has taken as the price of revenge, but would she only answer calls of those who have been betrayed? How would the subjective nature of betrayal make that work? Like if the targeted party doesn't think they betrayed anyone or if the person who is attempting the summon feels they were betrayed but they really weren't? Would she care enough not to harm the truly innocent? If not what stops from just being high cost hitman?

I'm not just looking for riot feedback, if you are reading this and have an opinion let me hear it. All perspectives are appreciated.