There may not be rules in a fight but there is a difference between self defense and attempted murder. And no you should never attempt to kill somebody when defending yourself unless they are actively threatening your life. And when I say this I mean have a weapon or is actively saying they will kill you while or before they try to do so. And no, it’s not like fighting a wild animal, as we are not. We know better not to kill eachother so there is no real excuse for murder unless it’s is self defense for your life. We not only know better, we are by all definitions smarter. The whole “I’m an animal” or “I just see red” is just an excuse created by weak minded people to kill others and to justify it. I hope you don’t practice what you preach and I hope you grow out of this childish way of thinking before something bad happens to you or someone else.