thinking about gong yuanzhi balancing the vague suicidality inherent in his perfectionism with his relentless pursuit of survival at all costs bc yea he absolutely thinks he should be dead (his own words), but to basically apologize for the fact that he Isn't and someone far more important than him Is, he must be perfect at his craft (poison), which involves hurting himself in ways that very much Could Kill Him (poison), but such a death would mean failure on his part, which is not allowed
dying in battle, also an imperfection, also not allowed. not that he'd be unwilling to do so, but he would do his best to avoid it on the basis that it'd reflect poorly on his skills as a martial artist (skills taught to him by gong shangjue, whom he cannot under any circumstances disappoint)
in fact dying at all would be depriving gong shangjue of yet another didi -- the #1 most forbidden most impermissible most not allowed of all time
but then along comes shangguan qian, who is someone gong shangjue chooses for himself just because she is who she is and not as a replacement for some other, similar relationship (at least, this would hold true in gong yuanzhi's eyes, even if no one else but he himself might see it that way)
i can only conclude that, were shangguan qian to actually cement her claim on that exalted wifey status, gong yuanzhi's estimation of the value of his own survival would shift pretty drastically from 1) gege 2) self to 1) gege 2) gege's beloved person, with "self" falling off almost entirely since his role in gong shangjue's life would become less clear to him (if he isn't everything to his gege, is he anything at all?)
like he really demonstrably only sees himself and his worth vis-a-vis gong shangjue and what he thinks gong shangjue needs him to be. which is perfect. because gong langjue, thanks to gong yuanzhi, never got the chance to be more than a perfect memory.
innnccchhheresting how the very specific skillset he is famous for (medicine and poison, life and death) reflects that perpetual balancing act inherent to his character