That’s not what I would call “manifestation,” that’s black magic. Which, needless to say, nobody should ever engage in.
I believe that causing other people harm will ultimately come back to haunt you and destroy your soul (aka, put you squarely into the territory of the “Dark Side”).
Even if you “only” wish something terrible to happen to someone (vs. actively doing something to harm a person), it’s an act of evil. Leave the punishment for bad deeds up to God… and trust that evildoers will get their just desserts sooner or later.
Of course, if you’re a Christian, you should go even further and try to forgive that person who did something bad to you. Forgiveness is really mostly for your own sake, not for the other person’s, and it can do wonders for you in terms of stress relief and peace of mind.
Try the Goodwill Manifestation to spread blessings to everyone you meet… even to unpleasant people. It’s a very simple technique, and you’ll see amazing things happen.