So re: Qin Su's death, one thing I'm absolutely certain of is that she did not just conveniently kill herself due to her high level of distress, at the exact moment most convenient to a person she was super mad at.
Because, frankly, mxtx is not that shitty a writer. She doesn't sweat the details or logistics of things, characters are allowed to coincidentally turn up in the right place to make the plot work and so forth, but these novels are intensely concerned with character motive and internal life. Everyone does things for their own reasons.
People do what the plot requires, but a defining feature of her writing is that everyone is fashioned into the shape of the kind of person who would do that thing in this situation. Sometimes whole scenes or subplots exist mainly to put on display the underlying cognitive patterns that justify as individual choices the kinds of things stock characters routinely do in genre novels, for no reason than that they are The Type Of Character who Does That.
If Qin Su was going to commit suicide about the bad news, there would have been hints that this was the direction her thoughts were trending during the preceding scene, where we're introduced to her reactions. And there aren't.
Her primary reaction is anger. She's scared to death when her husband paralyzes her and puts her on his dismemberment table to interrogate later for the name of her informant. She is contemptuous of his caring almost exclusively about what all these horrors could do to their reputation.
There is nothing in the scene to suggest she would, given the opportunity to denounce him to the cultivation world, choose instead to escape by knife.
The interpretation of this sequence that says she Just Did That really annoys me, because it requires ignoring basically every single piece of information about the character other than the fact that Wei Wuxian always thought since they were kids that she wasn't very bright.
Furthermore, it would be out of character for Jin Guangyao to have knowingly arranged a situation likely to go so badly for him, and wildly unusual for him to get so lucky if he had. This man has shit luck normally.
The sensible thing for him to do, in a universe where Qin Su just conveniently opted for suicide instead of ratting on him, would have been to take the ten to twenty minutes of prep time he had to work with to disappear her the same way he did nmj's head.
This might have required killing her first, since we don't know where he put it, but while I'm sure he didn't want to do that I'm equally sure he was entirely capable. He had a convenient scapegoat handy to blame for her disappearance.
He had no reason to allow her to be visible and capable of independent action when his cavalcade of guests arrived. But there she was, dazed but unrestrained. And then...cursed knife time.
Super convenient! She's dead and can't blab, and lots of important people saw her do it and saw how horrified he was and are disposed to be sympathetic. Works out much better for him than the risk of being blamed if she disappears.
So Wei Wuxian's assumption that jgy set the suicide up and compelled her somehow is the most logical inference. Neither of their characters is really compatible with the other scenario.
If Jin Guangyao had actual mind control powers he definitely would have used them a lot, so the most straightforward version of what happened is he used some technique or drug that would confuse her and suppress her cognition, then deliberately put 'cursed dagger that preys on your negative feelings and makes you kill yourself' within reach just before everyone entered.
I'm sure if it hadn't worked, and she'd just kind of stared into the distance while he talked his way out of the unproveable allegations and weaponized Mo Xuanyu's bad reputation and so forth, he'd have been happy with that outcome too, since it would still have meant a lot of important people saw her alive and not freaking out, and then he'd still have been able to torture her for information later. (Again, something I'm sure he didn't want to do, but absolutely would have.)
But this worked out well and got rid of two exposure threats at once while buying him sympathy points.
Although considering his shit luck, I wouldn't rule out that his plan only went as far as sedating her so she couldn't make trouble and he could show everyone how not paralyzed on his murder table she was, and he'd forgotten he had an evil dagger that compelled you to kill yourself lying around in reach of a woman whose ability to exert force of will he'd just reduced to nothing.
And he wasn't expecting that result at all.
#side note op what's your source for 'wwx thought she wasn't bright ever since they were kids?' #I don't think they knew each other. I do remember him thinking she didn't seem that bright though
#I don't think she was dim. not the sharpest knife in the drawer but to be fair there were some very very sharp knives in there #she wasn't politically motivated and she trusted easily. so what #she was kind and had a strong sense of justice and she was *brave*. (@helendamnationx)
Okay tbh that was my very slapdash and ungenerous synthesis of three passages. (Old fan translation excerpted because I do not have 100 dollars for danmei.) This one, from right at the start of the confrontation with jgy:
Although he wasn’t familiar with Qin Su, they had met a few times in the past, both being the descendents [sic] of prominent clans. Qin Su was the beloved daughter of Qin CangYe. Her personality was naive, but she had lived a comfortable life and was taught excellent manners. She’d never act in such a mad, violent way.
And this one, from her first appearance earlier in the same chapter:
...a trace of innocence was blended into her expression. Even her graceful features appeared somewhat childlike.
With this bit from wayyyyyy back in 'Refinement' when Nie Huaisang first appears.
The young masters were all around fifteen or sixteen. Because the sects all knew the others, although they weren’t close, they had seen others’ faces before.
From all this, and the parallel constructions of how 'everyone knew' Qin Su and Wei Wuxian's backstories adjacent to the second and third passages, I drew the conclusion that it's much more likely that Wei Wuxian's passing familiarity with Qin Su dates from the same before-age-fifteen casual social exposure alluded to with Nie Huaisang, than that she made any impression whatsoever on him during or after the Sunshot Campaign.
I also got the strong sense he regarded her as something of an intellectual lightweight, though admittedly he doesn't exactly say that, he just harps on the immaturity vibe. But like. We both got that feel, right? Right.
I think Qin Su is a very neat character with her one (1) entire actual scene of page time, which is part of why interpretations where she really just did that on her own bug me so much.
(The other part is that it falls into the pattern of readings that make the book dumber for the sake of exculpating blorbo lmao. If we want to excuse jgy from intentionally killing his wife the 'forgot about the evil dagger because he owns so much creepy shit' reading is right there.)
Also lmaoooooo some very sharp knives in that drawer. All of them however somehow idiots.