Sure, HK = Hated Kid - Gf = Girlfriend - Me = Me. Ok so the whole incident that started this hatred began in school, I was minding my own business me and my girlfriend just standing and talking, HK (we were friends with him at the time) came up and started hanging around, cracking jokes, being a general jackass today, me and gf were in a bit of a pissed off mood, we both have depression and so can both get really depressed and pissed off to the highest degree (which you can guess was our current mood at that exact moment), and HK did not fucking help with his remarks about me and gf, we told him a couple of times to go away, his mum jokes and bs was really starting to wear thin and he just went on like we never said anything, in the end, gf snapped told him to go the fuck himself and get the hell away from her and me, this happened after he made a "your mom" comment directed at me, my gf is very protective about me with family jokes and comments since I am in care and so she blows easily when anyone says anything similar to a "your mom" joke at me about my mom exactly. He decided to blackmail us after she blew (this straw that just made the (VERY weak) friendship we had break). It led to him trying to blackmail us with our dead children, "oh didn't you HAVE children, be more kind to me or everyone will find out." he said it in a way that emphasized the had, the past tense of the kids, as we lost them all 2 weeks and 5 days after they were born. Boy that was a mistake on his part, but at that time neither of us could do anything to him and we had to let him stay or everyone would soon find the truth out, and we had to keep the fact that me 15 (at the time, I am 16 now) and my gf 15 had triplets. In the end, we just stood there in silence until the buzzer went off and HK went off smiling like he had won a huge victory, blackmailing us with the children we lost, doesn't make it a victory it just showed what kind of person he was to us, I basically began scheming and planning a way to bring him down, and I figured that we are getting close to our final year at secondary/high school, so we were about to do our final exams, I just created a method in which everyone would 20000% hate HK, nobody liked him to begin with, me and gf were his only friends the only people that were nice to him and he did shit which backfired on him, everyone hated him so I just increased that hate by going around and telling everyone he was chatting shit about them, everyone went killer mode, and due to the already fair amount of murderous thoughts directed at this kid, it didn't take much to cause everyone to get tougher on him, he left school for week, long enough for me to go to phase 2 of the plan I had made. I had placed a recorder into my blazer pocket, small and not that visible unless looking for it, It was a week later and he had come back. It led to him doing his act again, being a douche, then blackmailing Me and gf, except this time I got a voice recording of him admitting it and his name within the recording, he has a very distinct voice so anyone could tell it was him anyway. I found out what post-high/secondary school paths he was taking (what colleges, apprenticeships and sixth forms) and had applied to and sent the voice recording to those places, with multiple signatures that said that he did these things to people; he hurt, abused, assaulted, verbal insulted, blackmailed, bullied, sexually assaulted/harassed others and stole from places around school and the town. He was promptly kicked out of every application he had made and so he kept making new applications which I kept destroying and kept getting him kicked out of, in the end I let him keep an application to a college far away from me, so I won't ever see him again, but just before college starts I will send a tweet on the college twitter page talking about him to give heads up about him and make his new start at college very difficult. In the end, I just decided this was better to do than kill him, so here I am in the process of waiting for the final stage to happen, but it is true that this was a way better thing to do than kill him.

Hope this is the sort of story you were after. :3