Sure it is.
Subjectively. People rate things on their personal scale all the fucking time. You can't go on social media without people sharing with you their top 5 movies or places to eat or vacation. Personal preference just usually isn't mistaken for objective truths until they start being uncomfortable truths about morality to the fearful and easily frightened.
It's not at all elusive. Justice could refer to the justice system which is merely a function of law or your subjective notion of what is just. What's elusive about understanding that?
You're not. You're trying to pretend your subjective preferences are object facts.
You've already admitted that you can't prove it exists and that this isn't the domain of physical reality which leaves your imagination.
So much crying and no sign of an objective fact anywhere.