Tbh most females who have these fantasies are usually some ugly nerdy schizo asian teenager or some super woke ass white bitch that is just very into asian culture, or just schizo fags
But woman aside, I think the psychology of why people like this type of shit is cause we tend to have a weird romance of "tragedy or dark figure", both in media and irl, which is probably why some woman love serial killers despite knowing they're straight out piece of shit.
It isn't just women who romanticize this; us guys also do the same thing. Lady Maria from Bloodborne literally massacred a whole fucking village just so they can find Kos before she committed suicide and live in her own hell in the Hunter Nightmare, and I still constanly jerk off to her despite it