The desire to oppress is not free desire. It is oppression. If someone has desire to go and shoot up a school, this is called oppression. The values of liberty, equality and fraternity allow free desire but do not permit oppression. If you think people should just freely oppress each other and there's nothing wrong with that, then I'm sorry but no stupid edgy argument you can make will convince me of your position.
Also, morality is not 'context-independent'. What a morality is is a system of establishing what is permitted as right and what is wrong. This does not mean context-independent. You seem to think that just because your system is a diagonalization makes it inherently better. Why is there no morality? Why is there no god? Why do these cause everything to be permitted? If your exigence for smashing the child rapist's skull is 'i wanted to', what prevents the child rapist from making the same argument? Are they not wrong in bashing in the skulls of any who try to prevent them? If you feel no sense of objective wrongness in the idea of such a thing, there is no more I can say to you.