Shen Yuan transmigrates into a powerful ice demon and just goes "Oh neat! Cool clothes and I don't have to worry about dying!" And kicks his feet up to chill. He doesn't recognize his name, so he assumes he's just some terribly irrelevant mob character who happens to be rich and strong and is just glad to run around PIDW without any consequences. He manages to gather that he's some widower with a young son, so he immediately assumes he's in the clear from potentially being an enemy of Binghe's. His son is so quiet, and demons aren't great with giving names, so he doesn't even know what to call the boy at first. It feels odd to ask him what his name is. He just does his best with raising him in a way that he can only hope isn't too noticeably different than the way the original goods did it.
His son is still very quiet, but as he grows, he and Shen Yuan become closer. The little prince is such a sweet boy! He makes Shen Yuan little arts and crafts and leaves them on his desk to find. Anything from flower crowns to vaguely menacing knicknacs made of the bones of small animals. He'd be more scared if his son didn't seem so expectant of praise for the work. A few of them definitely resembled cursed idols, but who was he to judge his little demon son? There aren't any child rearing manuals, but from his own PIDW knowledge, this seemed developmentally on-track for demon kids.
But apparently the original goods wasn't rich and strong without consequence, because he's hounded with political matters before long. They're flooding his office with letters, hounding him for meetings, begging him to manage affairs in his territory. He's coming into contact with all these other powerful demons and has to pretend he's even slightly aware of what they're talking about.
During one of these meetings, some guy mentions the heavenly emperor, and Shen Yuan's like, "oh??? Binghe's here??? Already???" And he's furiously reworking his timeline, but the other demons are like, "who tf is Binghe. We're talking about Tianlang-Jun" and internally he's like, "who tf is Tianlang-Jun". Some poking around later, and he realizes he's REALLY far off from Binghes rise. Man's not even born yet. Honestly it makes him relax even more. He uses the time to get to know Tianlang-Jun a bit, just because he's so curious about Binghe's father! A full true Heavenly Demon! Not as cool as Binghe, who has both heavenly demonic and human cultivation abilities, but still cool! He's also just curious about the kind of man his blorbo's father was.
For some reason, Tianlang-Jun already has a son??? Upon closer inspection, a nephew? The conclusion, of course, is that something must've happened to both of them for them to not even be mentioned in the book. Deeply unfortunate, but not Shen Yuan's problem. Or that's what he would say, but Tianlang-Jun is seemingly very fond of him now. Something about being fellow single dads? He keeps bringing Zhuzhi-Lang around and foisting him onto Shen Yuan for a "play date" with Shen Yuan's son. Zhuzhi-Lang is a good boy, and very quiet, but he's also visibly older than Shen Yuan's son. Like, by a lot. But Shen Yuan is no expert on demonic aging rates, so maybe half snake demons just... look like grown adults? At this point, it's more like Zhuzhi-Lang is babysitting Shen Yuan's son while Tianlang-Jun fucks off somewhere without him. How irresponsible! But Shen Yuan accepts the free labor.
Years pass, his son grows- he also ends up with ice powers, as well as a spatial ability, though if Shen Yuan is correct, that power is likely from a demon tribe slightly south from their territory. It sounds familiar, but there are tons of reused abilities in PIDW. Nothing odd here! Eventually his son starts taking on jobs that Shen Yuan never asked him to do, in an effort to prove himself to Shen Yuan and also help him out. So at some point he takes it upon himself to go to take something from some cultivators.
It's not until his son comes back with a sniveling Shang Qinghua in tow that Shen Yuan realizes he must be very, VERY off the mark on who his character is.
Linguang-Jun was not, in fact, supposed to raise the future Mobei-Jun to be a dutiful son (nephew) who lacked abandonment issues and had a habit of leaving offerings on his uncle's desk like a cat, but since he neither knew who Linguang-Jun was nor the fact that Mobei-Jun was supposed to get dropped in the human world to be hunted for sport as a child, this was exactly the kind of Mobei-Jun that he had. Shang Qinghua, aka the hack author of this goddamn novel, has the audacity to complain to Shen Yuan about how he raised Mobei-Jun too well. When Shang Qinghua groveled and wailed and begged for mercy, Mobei-Jun brought him to his uncle! Because he "had the final say" in whether or not Shang Qinghua could swear fealty to him! What the fuck!
Mobei-Jun accepts Shang Qinghua's fealty at his uncle's behest, and Shen Yuan uses this attachment as a way to keep track of the timeline, including when Su Xiyan will fall pregnant with Tianlang-Jun's baby. In the meantime, Shen Yuan uses his own friendship with Tianlang-Jun as a way to mark his progress as well. He's met her a few times since Tianlang-Jun keeps dropping Zhuzhi-Lang off so they can run off on their little dates, but it's too odd to ask either of them if he's gotten her pregnant yet, so Shen Yuan tries instead to drop hints to nudge Tianlang-Jun in the right direction.
Talking about the joys of fatherhood, how adorable babies are, how unfortunate it is that some species, like humans, have very short windows of their lives in which they can have kids, and can even miscarry... Tianlang-Jun seems to get it- or maybe he's giving the man too much credit, because suddenly Tianlang-Jun is offering Zhuzhi-Lang as a surrogate with the insistence that "as a half-snake, he's guaranteed to give you litters! Even with a few dud eggs, he'll definitely give you a nice batch!" And "the gestational periods are short too, so you can always try again! As a heavenly demon, he's also very hardy! Your kids will be healthy for sure!" Shen Yuan has to firmly and kindly decline, though that seems to oddly disappoint Zhuzhi-Lang, who has been standing off to the side the entire time. Good sir, stand up for yourself! You don't need to do everything your uncle says! Filial piety only goes so far!
Anyway it's not long after that Su Xiyan actually gets pregnant. He expects canon to unfold from there, based on Shang Qinghua's unused old notes- Tianlang-Jun getting put under the mountain, Su Xiyan getting captured and dying after giving birth, Zhuzhi-Lang getting stuck in snake form and trying to free his uncle- all very sad and very necessary for Binghe's rise to power. Except for some reason Su Xiyan is now at Linguang-Jun's doorstep?! With Mobei-Jun?! Son, why do you look so proud of yourself?!
Apparently Mobei-Jun, who continued to pick fights with human cultivators, habitually came across Su Xiyan and her martial siblings. Su Xiyan, recognizing him, always let him off lightly out of consideration for Linguang-Jun. She warned him that as long as none of his attacks were fatal, she would let him go: but that if he killed any of her martial siblings, he would either die at her hands or suffer in the Huan Hua water prison. In return, Mobei-Jun, who was basically a semi-regular figure at the sect now, noticed immediately that she had gone missing when he showed up at the sect one day and it was another older cultivator that crossed blades with him, instead of her. Fast forward, and he's busting her out of captivity, and dragging her to Shen Yuan after she tells him that Tianlang-Jun is in danger. Shen Yuan is gobsmacked. The Old Palace Master hasn't even called on the other sects yet! Su Xiyan was in captivity for less than a day! What the hell, Mobei-Jun?!
But he cannot scold his dear nephew, who is looking at him so expectantly for praise. Instead, he calls on Tianlang-Jun and Zhuzhi-Lang to let them know about Su Xiyan's whereabouts, and then calls on Airplane. This damn hack author deserves the burden of this dilemma too!
Really, it's too late to turn back now, so after shaking Airplane's shoulders aggressively enough, the man finally agrees to pull some strings at his sect. The Old Palace Master's request for aid is turned down, Tianlang-Jun and Su Xiyan are alive, and it's not long before the Old Palace Master unfortunately qi deviates while attempting to cultivate in seclusion. Su Xiyan gives birth safely to a baby boy, and the human and demonic realms are in an uproar when Tianlang-Jun announces their marriage, but there's really very little they can do about it.
On the bright side, the two realms never merge. Unfortunately, Tianlang-Jun and Su Xiyan getting together seemed to have started a bit of a trend, and now Mobei-Jun was asking Linguang-Jun for permission to court Shang Qinghua??? And other cultivators that he met at the wedding have been extending offers and invitations to Linguang-Jun???
Shen Yuan would like to retreat back to the northern mountains and never come back.
