Its more likely that I'd kill if it were in the heat of the moment, like, if I were to bump into a rape in progress, chances are I'd rip the rapist's knob off and leave them to bleed out, or cut their scrotum off and pour chilli sauce and powdered caustic soda all over their bare, skinless bollocks, and just leave them to scream their lungs bloody.
If I found out ex post facto, then oh boy, the poor fucking bastard would wish themselves never born. I don't think I'd kill them, at least not straight away, but more like, say, operate upon them, with no anaesthetic, castrate them, and then go into their heads. And remove their frontal cortex, trash their nigrostriatal tract also targeting Broca's and Wernicke's areas, controlling speech and writing comprehension. To leave somebody an aphasic, agraphic, parkinson's disease-afflicted, vertually paralysed shell of a person, capable only of suffering, unable to feel pleasure or happiness, perhaps damage their limbic system to leave them an emotional wreck too.
And of course, remove their eyes using concentrated sulfuric acid to burn them out, cut out their tongues, and hammer their fingers into bloody pulp, crushing their finger bones to mush, covering the wounds in dog waste to ensure infection. And then leave them, after branding their forehead, back, torso, stomach, arms, legs etc. with the word 'rapist'
No friend or loved one of mine would go through that, and the person responsible get away with it. Crucifixion and flaying alive would be a blessing compared to what I would inflict, were it premeditated after discovering that a friend was raped. My vengeance would be agonizing, slow, drawn out and terrible to behold. I would make the person wish they could speak or sign or write to beg for death. Only for that to be made impossible courtesy of said anaesthetic-free brain surgery..but all they would be able to do, is silently scream, and scream, and scream and silently fucking scream inside; for the remainder of their natural lifespan. And of course, severing the tendons, messily, with a rusty blunt drill bit in their hamstrings, ankles, elbows, fingers, toes etc. So between that and the inflicted parkinson's they would be unable to kill themselves, but just be forced to sit there silently screaming in agony, shitting and pissing themselves and having no choice but to lie their in their own bodily waste.
I hate rapists. I know what it does to people, I have known it happen to people I value greatly. I still, and probably always will feel bad, for failing to prevent a rape of a friend, because I chose to go to one of two parties hosted by the girl's friends, and went instead of the one she went to, to the one hosted locally by someone I was friends with as well as her.
If only I had gone to the other one. I couldn't have known, but still. I wish I had gone to the other party so I could have executed the raping piece of shite bastard grandfather fuck. The girl wouldn't tell me who it was or where to find them later after she came to me and told me what happened. Probably because she knows me, and knows that while by nature I am a kind, gentle, caring person to those who have not earnt otherwise, but also knows what I am capable of, given a damn good reason, she knows, exactly the sorts of things I am capable of doing to somebody, without the slightest hint of regret, remorse or squeamishness.
By nature, as long as somebody hasn't actively earned pain, I do not seek to dish it out, nor do I go round treading on people's toes so to speak, BUT, anybody who would mistreat my friends and loved ones, or abuses animals, or fucks kids. They, will find me to be one stygian ice-cold fucking bastard, who will not give up, back down or allow them to beg forgiveness.
I am every bit capable of waiting for years, even decades, before acting. To make sure that the stench of suspicion does not follow me around afterwards, I have a decent knowledge of forensic technology and procedures, and am, unfortunately for any such piece of muslim-sewage, patient, methodical, thorough and very creative. And in the case of such subhuman pieces of shite, not in the slightest inclined to grant forgiveness.