I mean I don't plan on murdering them. But extortion could work. I've been yearning to gain some sort of control and was even thinking of making a thread about getting the control I deserve for dealing with them for years
Do you have something that you could hold over their heads?
Also, I have asked the question a couple of times but, got no answer from you. Are your parents capable of repaying your actions in kind? It's an important question because you asked for a consequence free, way to do this.
So if you are going to use violence or blackmail, and the parents are capable of violence or blackmail themselves, then you might be in for much bigger problems.
For example, if I was an abusive alcoholic and the child I don't like tried to blackmail me, I might just have you committed. Tell police you've been threatening to kill people and yourself. When they got there, I could put on a really great act as a parent and the cops will swallow it, hook, line, and sinker. Might even do some self harm and blame it on you. That will not only let me strike back at you but, it would also diminish the power of the blackmail material because, who is going to believe a crazy person that is a threat to other people and themselves?
Do they have anything they can hold over you? Do people in your life know you're Trans? Because a parent that really disliked you might return a blackmail attempt by outing you.
If you are going to follow through with this, you will need to be expecting the responses. Extortion and blackmail is like playing chess. You need to anticipate your opponents next moves and plan your counter moves. And even if you plan really well, it all might still crash in on you.
You are trying to leverage and hurt people. Hurt people strike back. You better make sure you have multiple plans and have thought out there potential responses very well. Or you are still heading for disappointment, or worse.