Wei Wuxian is cold. He shivers and moves to pull the covers he must have kicked off back over himself but the thin blankets of their bed are nowhere to be found, even as he gropes around himself in the dim light. Their bed feels oddly hard too; Lan Wangji, statuesque jade sculpture that he is, makes a very firm pillow but their bed is pleasantly springy and what he's lying on feels more like the hard floorboards in the main room of the jingshi or even rock. He feels around some more and scrapes his knuckles unpleasantly and unexpectedly against a rough surface; stone wall beside him and stone floor below him means that he is definitely no longer in the jingshi.
His stiff muscles twinge unhappily as he uncurls himself and the left side of his chest burns with a familiar pain. He sits bolt upright and stops his hand just before it presses against the charred skin of the Qishan Wen Sect brand, only faintly visible against his dark robes in the flickering firelight. He stares down in disbelief, tugging the collar of his outer robe aside to get a better view of a wound he received twenty years ago in a body long gone, now fresh and barely starting to heal.
He pulls his robe completely open, nearly ripping the collar in his haste, and pats at his abdomen. The skin below his navel is smooth and soft, no ropy scar from where Wen Qing cut him open and pulled out the beating core of his spiritual powers to revive his little brother's soul. The very same core burns within him now, chasing away the phantom frost that nips at his fingers and toes and filling him with warmth.
All that warmth rushes to his face when he looks up at the fire and the man leaning against the wall beside it, sleeping as rigidly as he always does when he isn't wrapped around Wei Wuxian. The dark red of Wei Wuxian's underrobe, wrapped around Lan Wangji despite all of his protests after his own clothes were destroyed, looks even darker in the dim glow of the fire, almost down to embers now.
Wei Wuxian doesn't feel any need to worry about why he's back here right now: if it's the incense burner, then he'll wake to his own bed eventually, and if it's not, that's a problem to deal with once his husband is awake. For now, he pushes himself to his feet, marvelling at the ease with which his body moves and the distance he can see even in the gloom of the cave. He really had been a prodigy and Mo Xuanyu's body has yet to reach this level for all their vigorous efforts in dual cultivation. He puts his robe back in order and sets to gathering more fuel for the dying fire. Once he's fed it on miscellaneous shrubbery and coaxed it to the point of cheery crackling, he turns back to his sleeping husband.
Lan Wangji's posture is perfect but his face is marred with worry lines even in sleep and sweat gathers in the creases on his forehead. Wei Wuxian does his best to dab his forehead dry with his sleeve and Lan Wangji turns into the touch with a faint whimper, eyes fluttering a little. Usually Lan Wangji sleeps more soundly than to waken at a single touch but right now he's in pain and grieving and of course, the teasing that the younger Wei Wuxian delighted in earlier must have upset his delicate heart quite a bit.
He can't bear to watch his husband in pain without doing anything and in this case, it is much easier to ask for forgiveness than permission. Wei Wuxian grasps Lan Wangji's shoulders gently, tugging him far enough forward that he can get an arm behind him and carefully fit himself in behind Lan Wangji, trying not to jar his injured leg any further than he has to while making enough space for him to sit against the wall. He tips Lan Wangji's sleeping head back until the stiffness of his neck eases and his head lolls fully onto Wei Wuxian's shoulder.
The brand over his heart and the arrow wound in his left arm still burn when he moves but he can hold Lan Wangji comfortably upright in the crook of his right arm as he leans back against the cold cave wall. It's much warmer now with the fire stoked and their bodies pressed together through the thin layers of Wei Wuxian's robes. He should have done this the first time around. They would have slept much better huddled together for warmth instead of spending energy they couldn't afford to lose to fight off the cold.
He cradles his husband in his arms and feels himself start to drift off, nestling his cheek against Lan Wangji's hair. Even if this is a dream, it's a good dream to let him hold his husband like this, offer the comfort he was too afraid of rejection to give the first time they were here. A good dream.
(Well, first he has to remove his husband's very spiky hairpiece because it's stabbing him in the neck, clearly having been designed to be uncomfortable for the person wearing it, and also everyone else in the immediate vicinity, but after that it's all good.)
The scrape of scales on stone startles Wei Wuxian from his light doze but the muffled cry of pain that Lan Wangji makes at the sudden movement brings him to full awareness, spiritual energy coursing through his body in preparation for a fight. He even tries to reach into his sleeves for a talisman, aborts the futile movement halfway when the burn on his chest protests vehemently.
"Wei Ying." Lan Wangji twists in his arms and places a gentle hand right below the burn, soothing the inflammation with some of his own spiritual energy even though his leg is still broken because he's an idiot who has absolutely no grounds to ever scold Wei Wuxian about recklessness and they should both be conserving every bit of spiritual energy to fuel their inedia. "Only retrieving the corpses, not attacking."
"Lan Zhan, you don't need to fuss so much, it's not that bad, I just moved carelessly," Wei Wuxian says. He catches Lan Wangji's hand in his and twines their fingers together to preempt any further attempts to pass him spiritual energy before he remembers to worry about which version of his husband he might be talking to. His heart leaps into his throat. "When did you wake up?"
"Just now. Not a dream?" His gold eyes shine in the firelight as he looks up at Wei Wuxian from where he's put his head back down on his shoulder. He looks so young and exhausted, a far cry from the well-rested man that Wei Wuxian fucked into their bed last night, but the love in his eyes is the same.
"I don't think so," Wei Wuxian says. He watches Lan Wangji's pulse speed up, just visible under the dark fall of his unbound hair, and tightens his fingers on Lan Wangji's waist and hand, reminding him that they're here together. "I woke up earlier and you looked so lonely I just had to come over and snuggle with you. Also I was really fucking cold from sleeping on the floor in only one robe."
"Whose fault is that?" Lan Wangji says, looking pointedly at the shredded mess of his own robes, casualties of Wei Wuxian's attempts to make him release the bad blood in his chest. Only the lace overrobe is left intact to drape over the rest of the scraps like a particularly useless shroud, too delicate for Wei Wuxian to ruin without remorse but not substantial enough to keep any warmth in. Wei Wuxian laughs at the oblivious little fool that he was and holds Lan Wangji tighter, rocking in place with the force of his mirth.
"My fault, of course, you know I'm always trying to get you to take your robes off," he leers. For a long while, neither of them speaks again, relishing the comfortable silence of long-time partners and formulating their own thoughts on their situation. Then Wei Wuxian sighs. "I'm sorry, Lan Zhan."
"No need, Wei Ying."
"I know there's no need for apologies between us now, Lan Zhan, but I'm apologizing in the place of the me from back then. Or from now, I guess. I was cruel to you, even if I didn't realize how cruel. You were in pain and I couldn't even get over my fear of being rejected to offer you any comfort. So I'm sorry, for insisting you were my friend and then not living up to it when you needed me." He can feel Lan Wangji's eyes boring into the side of his face but he stares at the opposite wall of their little crevice and waits.
"I'm sorry too." He dearly regrets twisting his sore neck as fast as he does to get a good look at Lan Wangji's face, earnest and open despite the red creeping up his ears.
"You? For what? Being mad about me teasing you? Because I really did deserve that."
"Hurting you. Shoving you and then biting you." He traces the bitemark in the crook of Wei Wuxian's elbow with his free hand and Wei Wuxian feels a pleasant shiver up his spine even as he presses his lips together to muffle the sound of him laughing right in the face of Lan Wangji's tender sentiments. "Wei Ying. What?" Lan Wangji really is too precious like this, the stern look on his face softened by the firelight, the last vestiges of baby fat still filling out his cheeks under the untidy mess of his hair.
"Of all the things you could apologize for, biting me is definitely the most ridiculous."
"Why? You were scared of me, called me a dog. Wouldn't even sleep next to the fire." He's really just so cute when he's confused, Wei Wuxian can't resist the temptation to bully him.
"I was scared at first, sure, and then I was so turned on I couldn't think straight." Wei Wuxian smirks and pauses long enough to watch Lan Wangji's pupils dilate as the words sink in before he leans forward far enough to whisper right into the vividly pink shell of his ear. "I was afraid that you would see how hard I had gotten just from seeing you half-dressed with your teeth in my arm. Half the time when I was off 'looking for other ways out of the cave', I was just desperately jerking off to the thought of you in my clothes, biting right where you did so I wouldn't make too much noise and make you suspicious. You know how noisy I am, Lan-er-gege, and sound travels so far in caves—"
The rest of his filthy reminiscing gets cut off by Lan Wangji's mouth on his, a hand twisting into the fine hairs at the base of his neck to tug him down. He laughs into the kiss until Lan Wangji's very sharp teeth sink into his bottom lip in reprimand and he moans instead, the warmth flushing through his body turning sharply and suddenly to the burning heat of arousal, so much more urgent and pressing in this youthful body. He might be exaggerating how many times he got himself off for the sake of riling Lan Wangji up, but it was a memorable enough moment to fuel his fantasies for years afterwards. His cock is hardening very quickly against Lan Wangji's ass, warm and soft through the flimsy underrobe.
"That's twice now you've stolen my first kiss, Lan-er-gege," he mutters as he pulls back to rest their foreheads against each other. He grins as Lan Wangji shudders at the reminder, hips twitching up reflexively. Clearly he's not the only one suffering from oversensitivity. How far can he push him like this? "Are you going to steal my first time again too? Or will you let me show you how I touched myself when I thought about you?"
Lan Wangji slams his eyes shut and his hand over Wei Wuxian's mouth with a groan, barely letting him finish his sentence. His unfairly pretty eyelashes flutter against the smooth skin of his cheeks and it would look coquettish on anyone else but Lan Wangji, whose body is always honest when he can't bear to be. Wei Wuxian's mouth is firmly covered but Lan Wangji had to break their handhold to silence him, too overwhelmed to even perform the silencing spell. He takes shameless advantage of that to slide his hand into Lan Wangji's robe and over the familiar planes of his chest, skirting around his nipples to stroke his side soothingly.
Lan Wangji makes a strangled noise at the touch and Wei Wuxian stops immediately, unsure whether it was encouragement or protest. Lan Wangji opens his eyes again to give him a demanding look. When he lifts an eyebrow in question, Lan Wangji's blush only deepens further.
"It felt good. I just didn't expect the calluses." Mo Xuanyu had never advanced enough in his cultivation to get a sword and Wei Wuxian had not wielded Suibian in his new body for long enough to develop the calluses of his original body or the same ease and familiarity he had so painstakingly cultivated. No, the hands of his new body had stayed soft under Lan Wangji's tender ministrations, but right now his hands are rough and calloused from hard labor. Wei Wuxian's eyes light up and he nibbles and licks at the hand over his mouth, sucking gently at the sensitive pads of his fingers and relishing the quiet sounds that gets him until Lan Wangji jerks his hand away with a huff.
"Does er-gege prefer my hands like this? Do you like being able to feel how experienced I am at handling my sword when I have my hands on you?" Wei Wuxian croons, waggling his eyebrows outrageously just to push the innuendo over the top. He rubs little circles into Lan Wangji's side, purposely missing sensitive spots and keeping the pressure just the wrong side of tickling. He can't really move the arm that keeps Lan Wangji tucked against him, but he can stretch his fingers far enough to trace blunt fingernails along the sharp line of his hip through the thin underrobe, just shy of the waistband of his trousers and the visible bulge of his cock. That gets him an actual whimper and now Lan Wangji really does look like he's being bullied, face screwed up in frustration and eyes just a little bit teary. It's a very good look on him.
Unfortunately Wei Wuxian doesn't get to enjoy the delightful view for long because Lan Wangji promptly tucks his face against Wei Wuxian's shoulder, cruelly depriving Wei Wuxian of the chance to admire his husband, and bites very deliberately into the muscle at the base of his neck. Wei Wuxian's heart leaps in his chest, instinctive fear tensing every muscle in his body as his stomach drops into a bottomless pit before he goes fully limp, the pit in his belly filled to overflowing with a jolt of arousal that he can feel all the way to his toes but mostly in his cock. And then Lan Wangji doesn't let go, just presses his teeth deeper into his flesh until Wei Wuxian whines, high and nasal, and starts begging.
"Lan Zhan ah, Lan Zhan, please, please—" His voice cracks and he doesn't know if he's asking Lan Wangji to stop or keep going and then he loses track of his words entirely when Lan Wangji starts sucking at his skin just as he bites down a little harder before easing off and doing the same again, and again, and again. Meaningless noises drip from his lips and tears form at the corner of his eyes. He pants through his nose as his hips work desperately, shoving his cock against Lan Wangji's barely clothed ass in time with the rhythmic tensing of Lan Wangji's teeth around his neck. His head falls back against the cave wall but he can barely feel the sharp pain of impact through the tingling that suffuses his entire body, can feel only the heat that travels down the length of his spine and back up, the overlapping pleasure tangling into a seething knot at the base of his spine.
He loses track of time, of place, of everything but the overwhelming pain and pleasure that mix together to wash over and through him like a waterfall, filling him to the brim until he can't take any more. Lan Wangji bites down just a little bit harder, breaks through skin to draw blood, and Wei Wuxian tips right over the edge. He feels too large for his body, like a firework going off inside a closed room rather than open sky, pushing frantically against Lan Wangji to chase the last flickers of sparking pleasure before his body relaxes. He's practically floating out of his body now, too light and happy to be contained by physical form, tethered to the ground by the warm weight of Lan Wangji in his arms and the dulled pain from his various wounds.
Lan Wangji's teeth in his neck are replaced with his lips, laying gentle kisses tinged with the soft warmth of spiritual energy on his broken skin. Wei Wuxian's breath rasps in his dry throat and he lifts a numb and trembling hand to tug Lan Wangji away from his ravaged neck, bringing their lips back together in a sloppy kiss. Lan Wangji doesn't stop passing him spiritual energy, and now Wei Wuxian accepts it only to pass it back, cycling energy back and forth with every lazy, languid slide of lips and tongue. Wei Wuxian can't quite muster the coordination to breathe through his nose at the same time and he has to break away to gasp for air, staring at the ceiling instead of looking down at Lan Wangji's indecently smug face, the beautiful bastard. How is he supposed to calm down when Lan Wangji is smiling like that right in his face?
"Hanguang-jun is such a hypocrite, apologizing for biting me and then doing it even harder," he says breathily. His voice is absolutely wrecked but that definitely does it for Lan Wangji; the smugness drops off his face and leaves only open desire burning in his eyes like a banked fire. Wei Wuxian lowers his wet lashes demurely, "This husband must humbly apologize again. At that time, I had mistaken Hanguang-jun for a dog because he loves to bite so much, but he is clearly too refined to be such a lowly beast as a dog. He must surely be a divine creature like the xuanwu instead."
"Ridiculous." Lan Wangji pinches his side in retaliation and Wei Wuxian squeaks in indignation. "Wei Ying started it."
"I did, didn't I? But then you distracted me so well that I almost forgot you didn't answer my question at all," Wei Wuxian pouts. The hand he had curled into Lan Wangji's hair wanders down to his waist, tugging teasingly at the flimsy ties of his robe. "Does Lan-er-gege like it when I handle his sword?" He traces the line of Lan Wangji's cock through the sodden fabric with eyes and hand and enjoys the sound of Lan Wangji moaning in frustration right next to his ear. "Or does he need a demonstration of my skills first?"
"Empty words," Lan Wangji says, pressing a sweet kiss to Wei Wuxian's lips that belies the only half-feigned irritation in his voice. "Prove it." For all that he's mocked Jiang Cheng in the past for being needlessly competitive, he can't turn down a dare like that either. Lan Wangji really knows him so well.
"You only had to ask, Lan Zhan." That earns him an incredulous snort from the always elegant and refined Hanguang-jun and he still can't believe how much he loves this ridiculous husband of his. Suddenly he can't wait any longer to get his hand on Lan Wangji's cock, can't wait to bring him to the breaking point and watch Lan Wangji fall apart under him, over him, because of him. It's a matter of moments to undo the ties of the underrobe and once that's open, all that's left is to shove Lan Wangji's thoroughly soaked trousers down far enough to reveal his cock, flushed almost as dark as the underrobe and dripping onto the light smattering of hair under his navel.
The cold air of the cave on such sensitive and overheated skin makes Lan Wangji hiss but Wei Wuxian doesn't waste any more time on teasing, curling his hand around Lan Wangji's cock as he might when drawing an unfamiliar sword for the first time. Nothing works Lan Wangji up faster than making Wei Wuxian lose his composure entirely so naturally he's already slick enough with his own pre-come to ease the friction as Wei Wuxian strokes him ever so slowly to begin with, enjoying the sight of Lan Wangji's cock hardening even further beneath the larger hand of Wei Wuxian's original body. He can feel Lan Wangji's racing heartbeat against both of his hands, one wrapped around his cock and the other pressed against his chest over a phantom brand as if he could reach inside his ribcage to touch the heart that has held him so dear for so long.
"Lan Zhan, your face is really too thick, I can feel your heart pounding so hard yet your face is still as pale as your mourning robes," Wei Wuxian laments. Lan Wangji opens his mouth, probably to scold him for having the temerity to call him thick-faced when Wei Wuxian is the most shameless man in existence, but Wei Wuxian cuts him off at the pass, "I can't believe you were so rough with me when it's only my first time, biting me until I cried, truly Hanguang-jun is a beastly man."
Wei Wuxian takes great pleasure in forestalling his next attempt to respond as well, increasing the strength of his grip and tweaking a nipple harshly, and he watches in delight as Lan Wangji fucks up into his hand in a very impressive display of strength that leaves him panting against Wei Wuxian's neck as he attempts to form words in the face of such an onslaught of stimulation. Wei Wuxian is already hard again, inexhaustible teenage libido rearing its head once more, and he groans as Lan Wangji's thrusting presses his ass back against his cock, wet fabric dragging over the sensitive flesh.
"My Lan Zhan looks so lovely like this, all wrapped up in my clothes and my arms," he croons, nuzzling at the side of Lan Wangji's face, so warm and still pale. "Did you ever touch yourself like this, thinking about me when I left you sitting here in the cold to touch myself and think of you? I never did get this underrobe back, did you keep it afterwards? Tuck it away underneath your floorboards like the Emperor's Smile you bought for me? Hmm?"
He's being a shit now and he knows it, so it doesn't come as a surprise when Lan Wangji bites him again, higher up this time. It still sends shivers down his spine, sharp teeth digging into one of the most vulnerable points of his body. He knows it's not really a punishment, more of an encouragement, a way for Lan Wangji to egg him on without having to speak. But he wants Lan Wangji to use his words, so he slows the rhythm of his hand on his cock, not stopping, moving just enough to keep him on the edge and no more. Not until he uses his mouth for something other than biting.
"You keep avoiding my questions, Lan Zhan. The answers must be so embarrassing to keep you this quiet. Ah, ah, stop biting so hard! You don't have to answer if you really don't want to, I'm just curious. I never would have suspected back then if you did, I thought you were as pure and frigid as snowmelt, a truly upright gentleman. You've really disabused me of such notions though, by now I've been thoroughly educated in how wanton Hanguang-jun really is—"
"Wei Ying!" There's a telling little crease between his eyebrows and Wei Wuxian leans in to kiss it triumphantly.
"Please." It's half a request, half an order, and Wei Wuxian complies immediately, stroking his cock at a ruthless pace that leaves Lan Wangji entirely non-verbal again. Wei Wuxian almost comes just from watching those golden eyes roll back in his head with a startled moan.
"You only have to ask, Lan Zhan," Wei Wuxian says again, pressing his lips to Lan Wangji's slack mouth, and it's still true, he would give him anything he asked for, anything he wants enough to use his words rather than suffer in silence. His body is too small, too frail a vessel to contain the force of his love for Lan Wangji, and all the affection welling up in his chest comes spilling out of his mouth, "I love you, Lan Zhan, I love you so much, I'm so glad you're here with me, you're so good to me, the perfect husband, always want you, want to see you come just like this, just from my hands on you, I'll never get tired of it, love you—!"
Lan Wangji always looks like he's been carved from jade, but the sight of him in the middle of orgasm would put any masterwork to shame. The tension that pulls every muscle in his body tight, curls his fingers into desperate fists around whatever bit of Wei Wuxian he can reach, is completely absent on his face, suffused with a beatific expression of relief that pushes Wei Wuxian right over the edge after him, coming again into the space between their bodies. He's burning up, lost in the fiery rush of pleasure that sweeps through his body and leaves him spent and trembling.
Lan Wangji is shaking as well and Wei Wuxian belatedly releases his cock, threading both arms around his torso to hold him together through the aftershocks. He rests his head against the side of Lan Wangji's, dropping feather-light kisses along the slope of his shoulder, fully bared by the falling neckline of the underrobe. There's a lovely pink flush all the way down his chest and Wei Wuxian wishes he was talented enough with colored inks to capture his husband's beauty in a painting, but even a perfect picture could never live up to the real thing, hot and sweaty and deliciously disheveled and all his.
"Mn." A noise of discontent, and Wei Wuxian looks up from his very important project of marking up as much of Lan Wangji's upper body as he can possibly reach in revenge for the two very large and obvious bite marks on his neck. Lan Wangji is staring down at the mess on his stomach with a frown and Wei Wuxian reluctantly unwinds an arm to rifle through the shredded remains of Lan Wangji's robes.
He digs through the scraps until he finds a relatively clean piece and dabs gently at his stomach, trying to keep the underrobe and trousers as pristine as possible in deference to Lan Wangji's sensibilities. Wei Wuxian's robe and trousers are a lost cause already, drenched with the mess of two orgasms that is surely seeping into Lan Wangji's underrobe too. Luckily he can't see the back of the robe (even if the younger Gusu Lan disciples insist he has eyes in the back of his head) and Wei Wuxian isn't going to point it out if he doesn't realize it. He's gotten used to the convenience of the cleaning array that he'd invented and Lan Wangji had personally sewn into every piece of clothing and bedding they own, earning them the undying gratitude of the disciples who pull laundry duty and greatly reducing the number of times they have to change the sheets.
"All good?" Satisfied, Lan Wangji relaxes back into his embrace, pulling the robe closed for what meager protection it can offer against the chill and frowning at the dirtied rag in Wei Wuxian's hand. He's about to toss it into the fire when an idea strikes him that he can't help but voice. "Do you think we could use this rag to distract the xuanwu of slaughter? Surely the essence of an esteemed cultivator like Hanguang-jun would carry enough yang energy to attract a deformed divine beast—"
Lan Wangji smacks the dirty rag right out of his hand and into the fire in one smooth motion. "No, Wei Ying."
"Lan Zhan!" he whines with no real disgruntlement at all, hiding his grin poorly in the crook of Lan Wangji's neck. "In all seriousness though, we've probably riled the poor xuanwu up terribly by being so noisy and energetic where it can't possibly get at us. Even all those corpses can't be much more than an appetizer after four hundred years of starvation and living cultivators probably taste much better than dead ones."
"Doesn't matter," Lan Wangji says. "We can kill it."
"I know we can, we managed it when we were idiot teenagers, but that doesn't mean it's going to be easy—"
"Wei Ying." It's rare for Lan Wangji to interrupt him, but it's always important when he does, so he obediently shuts up. "You said last time that its shell was full of corpses and resentful energy. It will be very easy."
Wei Wuxian hopes he never stops being surprised and delighted by the way his husband's mind works, by the flexibility and understanding that he learned, not from the rules instilled in him by Lan-lao-xiansheng, but from thirteen years spent in the service of their shared promise, following the chaos wherever it led him and learning what the world looked like beyond black and white.
"How is your memory so good? Never mind that, Lan-lao-xiansheng is going to try and murder me for corrupting you," he sighs disconsolately. He had hoped that maybe he could get the man to like him if he managed not to plunge the cultivation world into chaos and slaughter countless people, but maybe that's been a lost cause since the day they met. "Are you sure? I don't have to use demonic cultivation right now. I could keep that door closed forever and let all the idiots who would try to follow in my footsteps bring disaster down on their own heads without any help from me."
"You don't have to, but you want to." As always, Lan Wangji is precise and accurate when he seeks to get to the heart of the matter. "You walked the crooked path then because you could walk no other, but the pursuit of knowledge and discovery brought you joy. I do not suggest that we publicize the more heretical applications of your knowledge but you have created many things that would serve to protect rather than destroy." Wei Wuxian is speechless for once, struck to his core at the depth of trust that Lan Wangji puts in him.
"Sticking to the single-plank bridge really isn't that bad, huh?" He can only echo the words that Lan Wangji quoted back to him at Koi Tower. "Will you help me again? Keep me from falling into that dark and narrow river?"
"For the rest of our lives." His ears don't even have a tinge of pink but Wei Wuxian's face is burning, forever weak to his husband and the way he easily professes such romantic sentiments. He presses a kiss to Lan Wangji's cheek and repeats these words back to him too, another vow to bind their lives together.
"That solves one problem, but even if we kill the xuanwu, that sword will still be in there, soaking up all of the energy of its death," Wei Wuxian says. "I want to destroy it." He surprises himself with the vehemence of his words but Lan Wangji only makes an encouraging noise and pulls his arms tighter around him. "I never should have brought it out of this cave in the first place, but now that we know what it can do, it has to be destroyed. I need to destroy it myself." So that no one can ever be tempted like he was. So that no one will die because he was blinded by revenge and didn't think about consequences or prices for the power he wielded so casually.
"Tricky." That's an understatement of the highest degree. Even before he crafted it into the Stygian Tiger Seal, that sword carried a miasma of resentful energy so thick that it could only be matched by the air of the Burial Mounds. Wei Wuxian doesn't think it ever quite gained sentience when he thought that he controlled it, but if they leave it here to absorb the energy of the xuanwu, it undoubtedly will and that would be a far bigger problem than any xuanwu. "Could you destroy it here?"
"I don't think so, not as it is right now. Melting it down might be the easiest way, but we definitely don't have the resources or energy to do that here. We could probably scrape together a good enough version of an evil-suppressing qiankun pouch if you do the sewing rather than me and you're willing to sacrifice your stolen money bag."
"Melting it down? Is that not how you forged the Stygian Tiger Seal in the first place?"
Wei Wuxian frowns in concentration. He recalls little of the Sunshot Campaign for a number of reasons, but his great (and incredibly arduous) labor of forging remains clearer than most of his memories. "It was a little more complicated than that. The resentful energy of the sword is strongly tied to the physical shape. It only accumulated so much power because so many fading souls latched onto the sword rather than anything else left behind; it was a weapon, the form of their violent anger towards the xuanwu. When I forged the Stygian Tiger Seal, I molded it gradually into the physical form of a tiger seal so that it would allow me to control many corpses at once, all without dispersing the resentful energy contained within the original sword. To melt it down fully would be to obliterate the sword's form and thus the purpose of the resentful energy with an overwhelming amount of yang energy."
"So destroying or deforming the sword's shape would make it easier to cleanse it of resentful energy?"
"In theory, yes. But I don't think even your Chord Assassination technique would be strong enough to cut it into enough pieces, not with the bow strings we've got on hand," Wei Wuxian says regretfully. Obliteration of the form that channels resentful energy towards a purpose really is the easiest way, but resentful energy that strong also resists any change in its containing form quite strenuously.
"No need. Wen Chao's sword is of high enough quality to suffice and it fell in the pool before he ran." Wei Wuxian opens his mouth to correct him before he realizes that Lan Wangji is absolutely right and he should have remembered that as well. When he had retrieved the black iron sword after escaping from the Burial Mounds, he had happened upon Wen Chao's sword at the bottom of the pool as well and used the resonance it held for its owner to track down Wen Chao quickly and easily. It will be the easiest thing in the world to find it again after finding it accidentally the first time.
"Killing the xuanwu the first time around would have been so much easier with a real sword. We're geniuses in retrospect, Lan Zhan," Wei Wuxian says with an air of woe, mostly unfeigned.
"At least we can put the knowledge to use now," Lan Wangji says, typically pragmatic.
"Right now? I'd much rather sleep some more before we have to deal with the corpse sludge inside the xuanwu's shell again. It was bad enough the first time when I didn't know to dread it and I'd rather not lose what little is left in my stomach."
"Good, because I wasn't going to let you get up anyway."
(When they do eventually get up and venture out into the main cavern, Wei Wuxian goes ahead of Lan Wangji in deference to his injured leg. Then Lan Wangji emerges into the main chamber of the cavern wearing his lace robe over Wei Wuxian's red underrobe and Wei Wuxian promptly trips over his own feet right into the water, which does absolutely nothing to help him avoid disturbing the xuanwu before they're ready to do battle, but it does mean he doesn't have to wash his clothes by hand since they get a very thorough rinsing in his panicked scramble for the shore.)