Chapter Text
Satoru’s smile dropped as he closed the door of the basement. He should’ve known that those cowardly higher-ups would pull some shit like that, sending kids to their deaths was their favourite pastime after all. Not even a full month into being a jujutsu sorcerer and Yuuji already died. He came back though, courtesy of Ryoumen Sukuna, the resident King of Curses.
That damned king was starting to actually piss Satoru off.
He barely kept his cursed energy under wraps. It rammed against the shaky boundary, each strike harder than the last. What if he listened to it? What if he let it out and watched it decimate those disappointments of jujutsu sorcerers? They wouldn't even know what hit them if he made Hollow Purple powerful enough.
Yuuji was too still. There was no rising of his chest and no twitching of his hands. Satoru couldn’t bear to think that the Yuuji on the cold, metal table was the same Yuuji that jumped him with open arms with his grin nearly blinding his Six Eyes.
“Do you two really wanna be here while I dissect him?” Shoko asked, pulling her gloves tight against her hands. He moved to answer but the words withered away as the pink-haired boy’s corpse slowly sat up. Ijichi yelped next to him, throwing his weight at the wall behind them.
Yuuji (it had to be Yuuji, it had to be) glanced down, seeing his nude body and shouted, “whoa, why am I naked?!”
If not for his contrasting emotions, Satoru would’ve cackled at Shoko’s dumbstruck face. He jumped up and slid over to the boy, “Yuuji! Man, you gave us quite a scare when Megumi said you came back with a hole through your chest!”
Yuuji blinked, his cursed energy spiking as Satoru spoke. He seemingly disregarded everything Satoru said and smiled, “Welcome back, Teacher Gojo!”
The sharp clap as their hands met cemented Yuuji’s aliveness.
Later, as Satoru was driving them back to one of his safehouses (yes, he was driving because as much as he teased Ijichi, he didn’t fully trust the man with important addresses), he questioned Yuuji. “So,” he started, drumming his fingers against the wheel, “how did you come back to life? Because I haven’t taught you RCT yet.”
The boy froze, shoulders hiked up and hands clenched in his hoodie. After a few seconds, he answered, “Me and Sukuna made a binding vow.”
His hands tightened around the wheel, pausing the spontaneous melody, “for real?”
“For real.”
He expected it but it still made him grit his teeth, “what did His Majesty want?”
Yuuji thought for a second, biting his bottom lip, “when he says the word ‘enchain’, he has control over my body for one hour. He can’t hurt any humans during that time and I can’t tell anyone about the binding vow unless I have his permission.”
“And he gave you permission to share it with me?”
A nod.
Satoru went back to drumming, no melody, just a single, steady beat, “‘He can’t hurt any humans’, was that the actual wording?”
Maybe his voice dropped or maybe it was something else but Yuuji shrunk into himself when Satoru asked that question. That made him feel even worse. Yuuji should take up space and shout with his voice but he instead whispered out his response, “he can only harm humans who have tried to harm him.”
“Huh, that’s fine then.”
“Really?” Yuuji was incredulous, his eyes nearly falling out of their sockets as he whipped his head around.
Satoru shrugged his shoulders, “I mean it sucks you made one with him in the first place but at least there’s some protection.”
“Sorry, Teacher Gojo. I’ll do better next time!” The boy nearly bumped his head against the dashboard as he tried to bow in the car.
A booming laugh filled the car, “You say that like you're gonna have more binding vows with Sukuna.”
“Tha-that’s not what I meant!”
Satoru didn’t blame Yuuji for the binding vow, the kid was just introduced to jujutsu sorcery and was sent to his death, he was vulnerable. Sukuna took advantage of that. He saw a panicking kid and grabbed at his chance for control.
He had no time to think about the two as he was running late to a mission. Slapping himself awake, Gojo Satoru left the house to take on the world once again.
–
True to his word, Sukuna brought Yuuji down to his domain to talk about binding vows. He opened his eyes to see thin clouds in a soft orange sky. That was different. It was usually a blue sky, the middle-of-the-day type of blue with birds chirping and wind brushing against his hair. Did time affect Sukuna’s innate domain?
Speaking of Sukuna, Yuuji looked around, the King of Curses was nowhere to be seen. The three times he’s been in his domain, Sukuna was always sitting somewhere in the flower fields, the bright red spider lilies clashing against his white kimono.
Yuuji turned to the mountain and jumped back in surprise. The simple overgrown mountain that he’s barely explored was completely overshadowed by the gigantic red torii gate that stood before it. Now, he may have a slow brain but he knew for a fact that the last time he was here, there was no red torii gate, let alone one of that size.
He still walked through the gate and into the mountain’s forest, he needed to find Sukuna after all. Yuuji hummed nonsensical rhythms as he ascended the uneven terrain. He pushed against jagged stone and pulled at hanging vines. It was like an obstacle course to get to the top with the run-ups and jumps he had to do but slowly and surely, he made it to the top.
Something the boy noticed along the way was that he didn’t feel tired or hear his muscles screaming at him as he hiked up. It was the same when he explored the mountain. Was it because his consciousness was in Sukuna’s soul and not his physical body?
Yuuji shook his head, that was too much to think about and he needed to hear Sukuna’s explanation on binding vows. Lifting his head up, he saw the King of Curses elegantly sprawled across a stone throne, moss and weeds winding around the base of the smooth rock. His four eyes were closed and his chest rose with a steady beat.
The boy froze before flailing around. Should he wake up Sukuna? He said he would tell Yuuji about binding vows but he was sleeping right now and Yuuji couldn’t muster up the courage to say something. He sunk to the ground in defeat, the damp dirt staining his pants.
The breath of a chuckle forced Yuuji’s attention to the throne again. Sukuna was upright, leaning against the arm of the carved stone with a soft upturn of his lips. “Sukuna!” Yuuji whined, “why didn’t you tell me you were awake?”
“I wanted to see your reaction.”
Yuuji pouted, “haha, very funny,” he fixed himself into a proper sitting position, “binding vows, tell me about them.”
Sukuna frowned, “manners, kid.”
“Oh, yeah, sorry,” the boy bowed, his forehead brushing against the ground, “please teach me about binding vows, Master Sukuna!”
Sukuna frowned even more, his lips nearly screwing up into a scowl, “don’t call me that.” He left the throne to join Yuuji on the ground, barely batting an eye at the dirt that was probably soiling his kimono. “As I said before, binding vows are verbal contracts. There are two types, binding vows with one’s self and binding vows with another person. We did the latter.”
“How would a binding vow with yourself even work?” Yuuji tilted his head.
“‘You give something up to gain something’, that’s the rule with binding vows with yourself.” Sukuna ran a hand through his hair, “a popular example would be giving up information about your cursed technique to gain an extra boost of cursed energy.”
Yuuji nodded along (he’s been doing that a lot, hasn’t he?) as Sukuna continued, “another example would be that I, hypothetically, vow to use only eighty percent of my cursed energy during a certain amount of time and anytime I have to fight outside of the predetermined time, I can use hundred and twenty percent of my cursed energy.”
“Then wouldn’t you just use your cursed energy outside of that predetermined time all the time for the extra boost?”
Sukuna shook his head, “intent matters just as much as words when swearing a binding vow. If I had the intent to use my cursed energy outside of that predetermined time all the time then I wouldn’t get that boost.”
Yuuji frowned, “aren’t there punishments for breaking a binding vow?”
“Only if you make a binding vow with another person. Breaking a binding vow with yourself isn't as dire, the most would be you losing that advantage unless there’s some life-altering condition that you added.”
The boy groaned as he buried his face in his hands, “then couldn’t someone have a binding vow that said something like ‘in exchange for not doing a cartwheel on Tuesdays, I get immortality’?”
“They could but it wouldn’t work. Even if they had the strength to back it up, the most it would do is increase their durability.”
“‘The strength to back it up’?” Yuuji glanced at Sukuna, who shifted his position, resting his cheek against his raised knee. His eyes were glued to Yuuji, watching him like a tiger stalking its prey.
Yuuji couldn’t help the shivers down his spine as Sukuna spoke again, “The more strength or power you have, the more leeway you have with binding vows. For example, if we both revealed our cursed techniques then I would get a bigger boost than you since I have more power. The same is for the reverse.”
“How?”
“The weaker you are, the less leeway you have. If a grade four and a grade one sorcerer made the same binding vow, word for word and intent for intent, the grade one would reap most of the benefits while the grade four would be scraping the bottom of the barrel.”
The boy fell backwards onto the ground, “that doesn’t sound fair at all!”
“Jujutsu sorcery is rarely fair.” Sukuna’s voice was dull, the words leaving his mouth were tinted with a layer of remorse (or was it something else?).
Yuuji rolled over, laying on his side while facing Sukuna. “Does power affect binding vows with other people?”
“Unless the person with more power threatens the other then no. It’s the wording and intent you need to look out for.” The King of Curses shifted again, leaning back on his hands and stretching out his legs, his sandals just a centimetre short of resting against Yuuji’s thighs. “That’s why negotiations and clarifications are important when making a binding vow with another.”
“Could you make a binding vow on accident?”
“There is the possibility but as I said before, intent matters. If someone didn’t want to swear a binding vow then they wouldn’t be able to.”
Yuuji hummed in acknowledgement. The atmosphere died down into a quiet calmness, wind flowing past in a silent performance. It was nice. Yuuji looked up at the sky, still the unchanging orange he saw before and remembered the torii gate.
“Hey, Sukuna.” the mentioned man blinked at Yuuji, “what’s with the torii gate?”
He grimaced, “you shouldn’t worry about it, it’s mostly harmless.”
“Mostly?”
“Let me confirm my theory first and then I’ll tell you.”
Yuuji huffed, “alright.” and just like that, he fell asleep. Maybe if he fought the slow blinking of his eyes, he would have felt Sukuna moving his head onto his thighs.
–
Sukuna brushed out Yuuji’s hair, dusting off the small clumps of dirt. They’re grateful he didn’t press on about the torii gate since they didn’t have a fake explanation to give him. A sigh left their lips as they looked at the torii gate, a structure that was in the original’s domain.
Was he corrupting them? Was his soul still active even though they replaced him? Will he slowly come back and drag them away from Yuuji?
Sukuna couldn’t have that.
”Enchain.”
The first thing they noticed was how comfortable the couch was. It looked like it would scratch against their hands like claws but instead, it slid against their palms like water. The second thing was how tired they felt. They knew this feeling, the aching of their stomach and the slowing of their mind.
Sukuna walked out the basement and into a surprisingly normal home. There were no gleaming marble walls or ornate decorations. There were bare beige walls and clean dark-wood floors. They didn’t have time to take everything in as their mouth watered at the thought of food.
With a quick survey of the available ingredients, Sukuna got to work. Rice in the rice-cooker, oil in the pan, beef cut into strips and vegetables washed, cut and left to the side. It was a quick affair, lasting less than ten minutes and they were left waiting for the rice to finish.
Their hunger dulled, becoming background noise as they wiped down the kitchen and thought. All they could do in their domain was to think and they were doing the same in the real world. If they guessed a rough estimate, they had about a week until Gojo met Jogo. two weeks until Yuuji met Nanami and two weeks and four days until Junpei’s death.
So they had two weeks and four days to train Yuuji to the best of their ability. Sukuna could leave the cursed energy manipulation to Gojo, they would take over everything else. How would they even go about that? Throw theory at the kid and hope he learned?
The soft ding of the rice cooker cut them off before they could continue thinking about it. As they served up the meal, they frowned when they realised they made a meal for two. Sukuna mumbled with furrowed brows as they grabbed another bowl and cutlery set. Maybe they could pretend Yuuji was eating with them.
It was silent. No creaking of the floorboards or muffled human voices from outside. Dead silence, It was just Sukuna and their meal in an empty house.
The door swung open before they could relish in their solitude and they heard him before they saw him. “Y’know, Yuuji, you should’ve gone to sleep ages ago. I can’t have you slacking off with training tomorrow just ‘cause you’re sleep deprived!”
Sukuna swallowed the rice, “don’t worry, the kid has been asleep for a while.”
They felt the atmosphere drop, a faint feeling of unease crawling up their body. Gojo decided to enter the kitchen with his cursed energy coiled tight around his fists. His cheery demeanour clashed against the distrust in his voice, “Sukuna! I was wondering when I was going to meet you!”
“Do not put up an act with me if you aren’t even going to try and stay true to it.” The beef melted in their mouth, the seasonings complimenting each other like perfection.
His grin changed into a sneer, teeth sharp and unforgiving, “you tryna play housewife or you tryna poison me?”
“As much as I would love to, there wasn’t any poison in this dwelling.” They took another bite, “eat it or throw it out, I don’t care.”
The white-haired man, with a little too much force, sat down across from Sukuna. He ate with bright cerulean eyes glaring into their soul. They shook their head with a sigh, exasperated. Honestly, if he didn’t trust them then he didn’t need to eat it. Was he eating just for his pride or something?
The contrast of their eating was laughable. Sukuna was consistent, chewing and swallowing in a steady cycle. Gojo shoved food where he had space, nearly choking on half-chewed rice. It took a tension-filled fifteen minutes for the two to finish the meal. It took another five for Sukuna to wash up the dishes while the sorcerer stared with a scowl.
They turned around, resting their weight on the kitchen island counter and met Gojo’s gaze. Sukuna despised how exposed they were, every vein and feeling dissected by those piercing eyes. If they focused enough, they would feel his cursed energy thrashing against the trembling boundaries. The white-haired man spoke first, pausing the fear in Sukuna’s soul, “how did you get control of his body?”
“The kid told you about our binding vow, did he not?” The rhetorical question seemed to make Gojo even more furious as the air slowly wrapped itself around Sukuna’s neck, “strangulation? A bit barbaric for someone like you.”
The pressure vanished as the man breathed in one, two handfuls of air. “Alright, alright. A civil conversation then, we’ll have a civil conversation.”
The implied threat sounded like self-assurance rather than a warning for Sukuna to stay in line. They still nodded, if he thought he had the upper hand then he’ll be less explosive for the lack of better words. “Is there a real reason for putting the kid in the basement? There seems to be enough space for him to live in the house.”
“For one, basements aren’t common in Japan, you would need to go through a whole process that the average human finds tedious as hell so most sorcerers don’t check for them when searching a house,” he explained, “and two, there’s a special type of curtain with no visible barrier linked to the basement. If I put that curtain on the whole house then that would draw some attention and we don’t want that now, do we?”
They figured there was some type of barrier in the basement since there was a gentle weight that left their shoulders when he left but a curtain with no visible barrier? Shouldn’t that be impossible?
A chuckle dragged them out of their thoughts, “your face is saying that that’s impossible but that’s one of the many things one can achieve when bullying a curtain expert!”
Sukuna’s eyes glanced at the clock, 1:19am glowing with a soft red. They pushed themself onto their feet with a sigh. Gojo straightened up, watching their every step with wariness. “Ten more minutes until my hour is done and I don’t want the kid getting a concussion from banging his head on the floor.” They said, rolling their eyes at the man’s mild paranoia.
He still followed them down, watching intently as they laid across the couch. Man, if Gojo kept watching them, they were going to punch him or something. A second later, he spoke, “where’s your bloodthirst and desire for chaos and murder?”
Well, he’s as blunt as ever, isn’t he? With a silent groan, Sukuna replied, “As you said, a vessel like him is one in a millions. His morals and beliefs are complete opposites of mine and so was his upbringing. I want to see his growth and whose values will reign supreme, his or mine.”
Gojo obviously didn’t believe their answer as he scoffed and muttered something under his breath. It didn’t matter to them as their hour came to a close and they drifted back into their domain, appearing next to the sleeping Yuuji once again.