I feel like people misunderstand the title of Mo Dao Zu Shi, or of what Wei Wuxian does as “demonic cultivation” (mo dao). It’s not. It is, however, what most people in canon THINK he’s doing
Mo dao messes with the cycle of reincarnation, which is why the Yiling Patriarch becomes so reviled. The term mo dao is actually used only ONCE in the novel - when Wei Wuxian notes that people called him “the grandmaster of demonic cultivation”
It uses living humans, extracts qi out of them, and involves the destruction of golden cores, brainwashing, and effectively vampiring living beings for the sake of power. It doesn’t use ambient resentment, it creates it by harming others.
The reason we’re continuously told (by people who know nothing of Wei Wuxian’s path) that he’s at risk of going insane is because that’s what mo dao does. It warps the mind and body because the source of resentment is within the user
Wei Wuxian calls his cultivation “the ghostly path” or “ghost cultivation” (gui dao). Hell, the only other person shown to match his expertise on the subject - Xue Yang - also calls it gui dao. Xue Yang !! He’d be delighted to call his actions demonic !! If he’s insisting on calling it “ghostly”, then that tells us that the difference matters
So what is gui dao ? First of all, we know that it doesn’t mind-control people as a baseline - that’s why Wei Wuxian ended up dying the first go around. We know that it utilises pre-existing resentful energy in the world to direct the dead
We know, also, that it requires a certain level of understanding of the dead. One of the spells Wei Wuxian creates is literally named Empathy.
We know that the power source is usually external (the Burial Mounds, the Stygian Tiger Seal), and that it, most importantly, doesn’t create demons. It creates ghosts and fierce corpses. And because of this, it likely doesn’t prevent reincarnation.
Why is the distinction important ? Because the former is what mo dao does. It creates mo.
We’re told the difference - very intentionally - in one of the earliest parts of the story, when Lan Qiren asks Wei Wuxian the difference between gui (ghosts) and mo (demons) and yao, and gets the correct answer
There’s foreshadowing littered all across the earlier chapters, actually. I might make a post on that some day
