I absolutely adore the way MDZS treats and talks about the concept of revenge. It says "Yes, getting payback on the things that hurt you is actually a stellar concept. In a vacuum. However, there is no true and quantifiable way to actually equate one evil deed to another, making the entire quest for revenge pointless because you will have no way of knowing when justice was actually met." Xue Yang killed dozens and tormented Xiao Xingchen for years, all for the sake of a lost finger, and still ended up unsatisfied, and all our hero has to say is why didn't you just take his arm and call it a day. Jin Guangyao taking the very neat, methodical approach to eliminating everyone who ever wronged him but by the time he gets there he gets taken out by another revenge seeker before he can even bask in it. Jin Ling wanting so so bad to hate everyone involved in his parents deaths but finding himself utterly unable to because they're all just messed up people and now he has to live with the fact that he's an orphan and that's just that. Jiang Cheng and Wei Wuxian hiding their good deeds from each other because they know it will just complicate everything even more and further muddy who was the wronged party. That one cultivator who goes on a hate filled tirade talking about how he's going to avenge to death of his parents and Wei Wuxian just replying "My life already sucked so bad, what more do you want from me?"
You can never have revenge. The world is too big and messy and you'll never just get the pure, satisfying moment of feeling like all your problems are solved because you harmed someone else. Purely because by the time you get there some unseen factor will be added to the equation and it suddenly won't count.
