At what point would you stop feeling sorry for a former traumatized victim?

[Anonymous]

For instance on several horror movies, there is an antagonist that is initially a victim but then takes it too far that you stop feeling sorry for them.

Let's say the antagonist suffered from a former HS classmate's constant torment. It was so bad that it left him traumatized with PTSD and social anxieties. Over the years he heals but then turns cruel and seeks revenge on his former tormentor, the wife and children. Then he harms or kills some random person that has nothing to do with his past.

Or a former raped victim that goes after her rapists but then takes it out on his children too.

At what point would you stop feeling sorry for a former victim?

[Kaneki05]

The more it becomes random. Think about it like this if said killer only killed their previous abuser or/and their family they aren't really a danger in society because it's an isolated issue.
It's not as if they're a danger to me or some other random.
Though even at the point it becomes more random don't mean I lose empathy for them as I still understand why they became like it.

[OneViewpoint]

At the point he/she becomes a liability to society.

[Vesuvius87]

At the moment they start targeting innocent children or random people. Once they harm a child (even if it's the perpetrator's kid.. what did the kid ever do to you?), they are too far gone.

[MemeSupreme]

let's say like even serial killers who were abused

i have sympathy for the version of them before they started doing fucked up things

[FreyaRed]

At the moment they project their aversions toward former oppressor on random people.

[Fromdusktilldawn]

Translator

this is how villains are mostly created: they were good at first but the constant torment and abuse transformed them into a monster

[beenherebefore]

When they make their personality all about their trauma and can't stop victimize themselves.

[Anonymous]

From the minute he or she turns to the dark side.

[In_Trance]

I think it's time to shut Netflix off for a while