When someone wrongs you or tries to pick a fight, stay chill, don't even acknowledge the issue, secrecy starts now. If there were witnesses, just shrug it off.
Later, a long time later they won't even remember what happened. Ofc don't let it happen again, but make them think you totally forgot about it, but you didn't.
Now comes the terror, cold calculated retribution. No police involved, no report, no records. You will use your intelligence as a sapient mammal, not teeth or claws like a badger. Time is on your side, it is absolutely necessary that no one knows anything about it. You will study your prey, know their habbits, and their routes. Set the webs like a spider, cast nets like a fisherman, trap like a hunter and this is ultimately important, the most powerful notion, they have to do something wrong to fall into the trap. Something illegal, something immoral, something that they might have gotten away with for years, but this time it's all going to come crashing down. One trap leads to another, the chess board was set by you, the dominos all in a row.
The best part is, if their clean, if they've repented, no harm will ever come to them. But if they trip, they will fall hard, very hard, you will make sure of that and you will be completely clean and untraceable. The trip will be the blame.
I have beautiful real-life accounts of this, when it happens it's magnificent. They don't have a clue and no one to blame but themselves. True karma isn't magic, it's calculated revenge. There is no such thing as a curse, but you can be the curse.