you can't actually say that a murderer is better than a serial killer or a terrorist is better than a murderer or a serial killer is better than a terrorist or any of that because they aren't all the same. like, every murderer isn't the same. I mean "serial killer" and "terrorist" are both words for murderers. so I don't even know why you're comparing a "murderer" to either of those things
but what I'm saying is, not everyone kills people for the same reasons. it could be because they had mental health issues, or because they were raised to think it was right, or because they were looking for personal gain, or because they were just mad
and all of those reasons could apply to terrorists or serial killers or whatever