Work Text:
It begins like this.
After the brat dies, he awakens in Sukuna’s domain, and immediately decides to attack him. Unsurprisingly, Yuuji rejects his deal to revive him, so Sukuna rolls his eyes and decides to do things the hard way. It’s almost too easy to slice the brat’s head off. Sukuna almost wishes Yuuji had put up a better fight. He sighs as he gives Yuuji’s corpse an uninterested once-over, then turns away–
Only to find himself sitting atop his throne, with Yuuji standing below him.
It takes a second for Sukuna to realize that, somehow, they’ve returned to their exact positions when Yuuji had died and appeared in his domain. It takes slightly longer for his vessel to come to the same conclusion, blinking owlishly up at Sukuna.
“Wha–How’d you bring me back here again?” he yells, balling his hands into fists. Sukuna suppresses the urge to roll his eyes—didn’t he realize fighting against him was useless? Still, Yuuji’s face is an open book. It only takes Sukuna one glance to know that his confusion is genuine, and that he isn’t the cause of what had just occurred. At least, not knowingly.
He leaps and lands nimbly at the bottom of the pile of bones. Yuuji stiffens, eyes narrowing as he moves into a battle stance. “Hey–” he starts, but that’s all he gets out before Sukuna slices his head off his shoulders. There’s a dull thud as his body falls to the ground, and this time, Sukuna keeps his eyes fixed on it. Perhaps there was something he missed. Perhaps–
He blinks. He’s on his throne. Again. And Yuuji’s below him. Again .
Well, Sukuna muses, tapping his fingernails against the armrest. This is new.
There’s anger in Yuuji’s expression this time. “You!” he yells, and rushes up towards Sukuna, shoes skidding against loose bones. “What did you do?”
He swings a fist only for Sukuna to grab his arm and knock him off balance in one fluid motion. He lands at Sukuna’s feet, winded, and before he can stand Sukuna leans down and grabs his cheek with one hand, tilting his head up so their eyes connect.
“Brat,” he drawls, unamused. “You really think I’m the one who’s causing this?”
Yuuji’s eyes widen. “Y-You’re not?”
Sukuna sighs. He frees Yuuji and leans back against his throne, head in hand. “No. Why would I create a time loop, anyways?”
Yuuji’s mouth falls open. “A what?” he asks, disbelieving, but Sukuna ignores him. He’s not entirely sure about it himself, but what else can it be? A time loop is the only explanation for why the two of them keep repeating the events of Yuuji’s initial death.
Then it clicks— Yuuji’s death —the loop had begun after Sukuna had killed him. He turns back to his vessel, who apparently senses that Sukuna’s realized something because he immediately raises his eyebrows when their eyes meet.
“What?” he tilts his head. “You’ve got a weird look on your face. What’re you thinking about?”
Sukuna rises. Yuuji steps back, distrustful—a smart move, though ultimately meaningless.
“You,” Sukuna replies smoothly. The last two times, he killed Yuuji through decapitation. Maybe something else would work. “The answer lies with you.”
He moves fast—fist tearing through Yuuji’s chest, shredding his insides to pieces. He wraps his fingers around Yuuji’s intestine and rips it from his body, entrails falling to the floor seconds before the boy’s corpse does.
Sukuna pays it no mind. He absentmindedly wipes his bloodied hand on his kimono as he glances around his domain. Last time, he’d focused his attention on Yuuji’s body, and seen nothing. Perhaps he’s been looking in the wrong place. Crimson water ripples around his feet as he slowly walks, searching for any clue that could be of use. A message, a warning, an exit–
He is sitting on his throne.
Sukuna huffs, amused. This may be more difficult than he thought, but no matter. He stands and that’s when he notices that the bloodstain on his kimono is now gone. Interesting.
Below him, Yuuji staggers to his feet, one hand clutching at his chest, expression one of shock and pain. It’s clear that he feels everything Sukuna inflicts on him, even after his ‘death.’ When their eyes meet, he sees for the first time, fear reflected in Yuuji’s own, and something akin to satisfaction swells in Sukuna’s chest. Yes, this is how his vessel should look—how all things should look when they see him, terrified of his power and strength. His blood thrums with a simmering hunger that’s been suppressed for a thousand years, a growing desire to destroy, to kill.
He takes a step forward. Cursed energy swirls around him, thick and suffocating. Red eyes lock onto brown, and Sukuna’s lips twist up into a grin. Getting out of the loop can wait. For now…
For now, he’ll hunt his prey.
***
By the fifteenth loop, Sukuna decides that he’d been right to focus his energy on killing his vessel.
For one, it’s entertaining. He savors the thrill that rushes through him whenever he rips Yuuji’s body apart, allowing himself to fight with a brutality he hasn’t experienced in a millenia. There’s no grace to it—just pure, raw, savagery. Skin tears like paper beneath his teeth. Claws slice through sinew and tendons. Blood sprays the ground, the walls—painting it all a beautiful shade of crimson. And then it repeats—again and again.
It’s freeing. It’s fun. It’s everything Sukuna had missed and more.
Sometimes he makes it quick. Sometimes—most times—he drags it out, makes Yuuji suffer, allows him to run or fight back and relishes the way he so desperately tries to win. It’s good that his vessel hasn’t given up yet—though Sukuna had expected he wouldn’t. If there’s one thing Yuuji is, it’s tenacious. He’s strong, and he never begs, never pleads for mercy. He may be afraid—but he isn’t a coward.
Sukuna can admire that. It’s why every now and then he allows Yuuji to get several hits in—not enough to truly hurt, but enough to keep the boy going, a reward for his perseverance. The longer Yuuji continues fighting, the better, after all.
He thinks they’ve made it to loop thirty when Yuuji manages to catch him off-guard for the first time.
Before he manages to rise from his throne, a fist collides with his cheek, sending him—and the chair—reeling backwards. Streaks of black ignite from Yuuji’s hand. Had Yuuji’s continued deaths caused him to level up so quickly that he could now master black flash? Though Sukuna’s ego is mildly bruised, he has to admit he’s impressed—just slightly.
He’s on his feet in a blink, already recovered. When Yuuji comes at him again, Sukuna ducks under the swing and smashes a fist into the boy’s stomach. There’s a satisfying crunch of bones before Yuuji flies back with a choked gasp in the shallow waters. Blood dribbles from his mouth, and Sukuna knows he’s ruptured some internal organs. It won’t be long, then.
“Not bad,” Sukuna drawls, walking towards the boy. “You’ve gotten stronger. Not strong enough, though,” he adds with a grin, dragging a nail across Yuuji’s cheek.
Yuuji doesn’t turn away. “Do it,” he snaps, unflinching. “Just get it over with.”
Something hot and heavy fills Sukuna’s chest, something he hasn’t felt for a while. A different type of hunger. He rakes his eyes over Yuuji’s broken body, his heaving chest and bloodstained lips.
“I’m impressed that you haven’t lost your fighting spirit,” he continues, trailing his finger down Yuuji’s cheek to his throat, tugging at the collar of his uniform. Yuuji hasn’t noticed it yet—Sukuna’s rapidly growing appetite, the lust burning in his eyes. “Though I wonder how long you can keep it up.”
It’s only when he rips Yuuji’s shirt apart that realization sets in.
“ You– !” A hand around Yuuji’s throat cuts him off and slams him into the ground, pinning him there as Sukuna tears away the rest of Yuuji’s clothes. Yuuji chokes, eyes wide, one bloodied hand scrambling to pry Sukuna’s fingers away from his neck, but it’s useless, of course. Because here, in this time loop, Sukuna is king.
And a king takes what he wants, when he wants. He releases Yuuji’s neck just as his lips begin to blue, positioning himself between Yuuji’s thighs as his vessel gasps for air.
“Don’t,” he wheezes, voice rough and battered, but Sukuna barely hears him. His cock is already rock-hard when he takes himself in hand, free arm holding Yuuji down as he positions himself against his hole. “No, no, stop– ”
Sukuna pushes in.
He almost lets out a moan at the feeling as he sinks into the warm, tight heat of Yuuji’s ass. “Fuck,” he hisses and Yuuji shrieks, helplessly thrashing against the cold, wet ground as Sukuna sets a rough, relentless rhythm. He’s missed this feeling. It’s almost euphoric, reminding him of his glory days during the Heian era, when he’d murdered and pillaged to his heart's content.
It’s different with Yuuji, though. He grins at the sight of his shaking, screaming vessel beneath him, tears leaking from his trembling eyes. His breaths are ragged, pained,but when he speaks it’s laced with cold, biting anger.
“I’ll kill you,” he hisses, even as Sukuna fucks into him, even as he bleeds out into the water. “I swear it. I’ll kill you.”
Sukuna just laughs. “I look forward to it,” he purrs, high on pleasure and power and the taste of death, and comes.
***
53
He takes Yuuji on his hands and knees this time, claws pressed against his jugular.
“Slut,” he taunts when Yuuji’s cock grows hard, even though he knows damn well he’d been aiming at Yuuji’s prostate the whole time. It’s fun to see the shame in his eyes, the way his lower lip trembles in humiliation. “You’re such a fucking whore. You love this, don’t you?”
Yuuji's jaw stiffens. “I’ll kill you,” he grits out. “I’ll rip you apart, you— Augh !”
Sukuna twists a nipple, hard. “What was that?” he jeers, as Yuuji does his best to muffle his groans. “I didn’t quite hear you.”
To Sukuna’s disappointment, his vessel doesn’t rise to the bait this time, not even as Sukuna fucks several sharp gasps from his throat. Oh well.
There’s always next time.
***
98
Yuuji’s breaths are hot and wet against his cheek. He’s half-slumped across Sukuna’s bare chest, sweaty bodies pressed tight against one another as Sukuna holds his waist, forcing him to remain in position. They’re on Sukuna’s throne, Yuuji straddled across his lap, thighs trembling from the exhaustion of being forced to bounce himself on Sukuna’s cock.
“S-Stop,” he whispers, when Sukuna shifts inside him, ready to go again. “Enough. I- I can’t–”
“Yes you can,” Sukuna cuts in. He pushes in deeper and feels Yuuji clench around him, a soft whimper escaping his lips. He looks beautiful like this—broken and exhausted, drained of all energy to fight. It makes Sukuna smile.
“You can and you will.”
***
He thinks it’s around the 200th loop when the novelty begins to wane. There’s only so many times you can kill and torture a man. As for Yuuji—Sukuna’s eyes flicker to the motionless body before him. The brat’s heart rests in his hands, ripped whole from his chest.
He supposes Yuuji’s reached his limit. He’d stopped fighting back against Sukuna anymore, though no matter how many loops they live through, the hate still burns in Yuuji’s eyes.
And he still clings onto that stupid, naive promise: “I’ll kill you one day, Sukuna.”
Sukuna laughs at him, every time. “Fool,” he says, with his signature, vicious grin. “The only being in this world strong enough to kill me is myself.”
***
230
Yuuji’s body sags heavily on his lap. Sukuna’s fingers slide through his hair, soft and slow, as the brat’s labored breathing echoes throughout the domain.
He’s waiting.
Throughout all this time, Sukuna’s never stopped to wonder if each loop actually has an end point. He knows they reset after Yuuji’s death—that’s a given. But what if Yuuji never died? If Sukuna kept him alive, would a set amount of time need to pass for the loop to end? Or would it continue indefinitely?
“What are you doing?” Yuuji sounds tired. Drained. He hadn’t even struggled when Sukuna pulled him onto his lap.
“Well.” He plays with a string of pink hair. “I’ve killed you hundreds of times, brat, but we’re still stuck here—so I’m trying something new. Perhaps the key is to wait.”
Yuuji doesn’t reply. Sukuna hadn’t expected him to, but he has to admit that the boy’s recent detachment is getting annoying. Like an itch he can’t quite scratch. Maybe it’s because he’s gotten so used to Yuuji’s fierceness at the beginning, when every loop promised a battle, a chance to spill blood. He knew his vessel was only human, but there was a part of him that expected more .
Yuuji takes a sharp, ragged breath.
“Do you think,” he says, voice quiet, “that perhaps it’s your death that will stop the loop, and not mine?”
Sukuna freezes. A heartbeat passes—a heartbeat that echoes so loudly in Sukuna’s ears that for a moment, it’s all he can hear—before he wrenches Yuuji’s head back, forcing their eyes to meet.
“You want to say that again?” he hisses, spitting the words out like venom. “You little shit—you think I’m responsible for this mess? You want me to fucking kill myself? Is that it? I’ll kill you.”
“Do it then.” Yuuji’s gaze never wavers. “It’ll just reset, won’t it?”
Sukuna’s eyes narrow. “You–” he growls, but in the next breath he finds himself atop his throne, his anger burning even hotter within his veins. Fuck. Fuck. So waiting out the loop doesn’t work. He’s so frustrated that he wants to break something. Rip something apart. Yet when he turns to Yuuji slumped at the bottom of his throne, he can’t find it in himself to move. There’s no point. Like Yuuji just said—the loop will reset.
That’s when it hits him.
Sukuna’s losing control.
The truth is clear as day—he’s just been ignoring it. Ever since the loops began, Sukuna and Yuuji became prisoners. The great King of Curses had been rendered powerless in his own domain, and so he’d turned to Yuuji—the only thing weaker than he is—to regain a sense of control. He owned him. Yuuji was his —but now Yuuji’s changed, and Sukuna realizes he’s once again powerless.
And for the first time in a long time, Sukuna feels fear.
***
???
He’s lost count of how long it’s been.
He stays away from Yuuji now, leaves him alone whenever the loops reset, and Yuuji never moves from his position. Sukuna hoped that with time, his vessel would return to him by his own volition. But Yuuji never acknowledges him, and with each passing loop, the fear in Sukuna’s heart grows stronger.
It feels like an eternity has passed before Sukuna decides to try and talk. When he sits besides Yuuji, his vessel doesn’t move. If not for the gentle rise and fall of his chest, he could almost be mistaken for a corpse.
Sukuna looks away. “You know,” he begins, voice echoing in the silence. “I’ve been thinking about what you said. That the loop ends with my death.”
No reaction. Yuuji stares straight ahead, eyes blank. Sukuna keeps going.
“I died once,” he continues. “A long time ago, when those bastard sorcerers hunted me down.” He can’t keep the disdain out of his voice when he says it, though it pleases him to know that they all eventually met their own gruesome ends. “I spent a thousand years immersed in nothingness, until I woke in your body. A thousand years, boy. A thousand years, hovering somewhere between the realm of life and death.”
A chill claws up his spine at the memory. He shakes it away. “I don’t wish to experience something like that again,” he confesses, and it’s probably the most honest he’s ever been with a human. “If I die here, there’s no proof that I will revive, like you.”
Something shifts in the corner of his eye. Sukuna turns, and sees Yuuji looking at him with an expression he can’t quite describe.
“What do you plan to do, then, if you don’t want to die?” Yuuji asks cautiously. “We’ve exhausted all other options.”
Sukuna fiddles with a bone next to him, thinking. “I suppose we can stay in this loop.”
“Then you’re a coward.” The reply comes sharp, swift. Normally, this would’ve resulted in a swift execution, but Yuuji seems to have realized that Sukuna isn’t hurting him anymore.
He ignores the insult. “Would it be so bad?” he counters. “Think about it. Out in the real world, you’ll live forever as a target. Those higher-ups will never stop wishing for your death. Here, you can live for eternity.”
“With you .”
“With me,” Sukuna confirms. He leans close. Yuuji doesn’t pull away. A good sign. “You already know I will no longer hurt you.”
Yuuji rolls his eyes. “And I totally believe you,” he snaps sarcastically. “After all this time—you haven’t changed a bit. You just want to protect yourself while controlling me.”
“That’s true.” There’s a look of surprise on Yuuji’s face when he confirms it, obviously not expecting Sukuna’s honesty. “But this is the best way to save the both of us. And if you don’t believe that I’ll never hurt you again, we can make another binding vow.”
He wraps his fingers around Yuuji’s wrist. He trembles underneath his touch, but allows Sukuna to draw him close. His lips part softly under Sukuna’s own when they kiss, gentle and sweet, and when they part Sukuna thinks he sees, for the briefest of moments, a flicker of hesitation in Yuuji’s eyes. But then the boy pulls away, standing as he does so, and when he looks down at Sukuna again it’s with sadness, and maybe even a little bit of regret.
“I don’t believe you,” he says. “And even if I did, it doesn’t undo everything you’ve done to me, all the pain and suffering you put me through. You tortured me, Sukuna.” He lets out a little laugh, like he can’t believe what he’s saying. “Did you really think I could just forget that? Because you left me alone for a bit?”
He runs a hand through his matted pink hair, suddenly looking exhausted. “Maybe I can’t ever kill you,” he continues, with a long, deep breath. “But I won’t let you get your way. If you want to get out of this loop—you’ll have to do it yourself.”
Their eyes meet again. There’s a beat of silence, but before Sukuna can say a word, Yuuji is speaking once more.
“You know,” he muses, “if you do manage to get us out of here—who knows? Maybe we can start over. Fix whatever this is between us. But if you don’t, we’ll just continue reliving this hell forever.”
He kicks at a bone on the ground, sending a ripple throughout the water. Sukuna’s chest suddenly feels tight.
“Yuuji–” he starts, but then he blinks, and the world resets once more.
***
Time passes. Loops begin and end. The tightness in Sukuna’s chest doesn’t go away.
He remembers the sorcerers who killed him once, of the way he was trapped for centuries toeing the line between something and nothing, of the coldness and helplessness of his solitude.He remembers the taste of blood on his tongue, the ripping of flesh beneath his claws.He remembers his own voice, laughing, Fool, the only being in this world strong enough to kill me is myself.
He remembers the softness of Yuuji’s lips on his own.
He stands.
Silently, he descends from his throne, robes fluttering around him.
Yuuji looks up at him when he reaches his side, eyebrows furrowed. He starts to speak, but Sukuna leans close before he does, pressing their lips together one last time.
When he steps back, the tightness in his chest is gone. Perhaps this would work. Perhaps it wouldn’t. But to stay in this perpetual world, trapped for eternity is to resign himself to the same fate as his first death.
A sharp, jagged pain explodes inside him when he thrusts his hand through his chest, tearing out his own heart. The last thing he sees before the world goes black is Yuuji’s face, his eyes wide in shock, lips parting around Sukuna’s name as he reaches out for him.
It makes him smile.