The 5th Special Grade | Jujutsu Kaisen

The morning air was crisp and cool, carrying with it the faint scent of pine and damp earth. The Danish sorcerers had established their training ground in a small clearing near their temporary base. The field was marked with rough dirt patches and scattered rocks, a fitting arena for sparring.

Furōkawa adjusted Onamazu, now resting on his back in its oar form, and grinned across the clearing at Emilia. She stood tall and imposing, her muscular frame a testament to her unique cursed technique, Super Hypertrophy, which allowed her to amplify her muscles with cursed energy. Even in a casual stance, she radiated power, her presence intimidating to anyone unfamiliar with her.

"Ready to lose?" Furō teased, rolling his shoulders. "Because I've been practicing my dodging skills. Not to brag, but I'm basically untouchable now."

Emilia smirked, cracking her knuckles as her arms swelled slightly, the cursed energy pulsing through her muscles. "Untouchable, huh? Let's see if your feet are as fast as your mouth."

They started slow, exchanging light jabs and feints. Emilia moved with surprising speed for her size, her strikes precise and deliberate. Furō ducked and weaved, using Onamazu in its oar form to parry her blows while the toxic mist at his feet stayed inert, a silent observer to their sparring.

"You're holding back," Emilia said, throwing a quick jab that Furō narrowly dodged. Her fist left a crack in the ground where he had been standing. "If you're going to mock me, at least try to keep up."

"Hey, I'm trying to be polite," Furō replied, grinning as he swung Onamazu in a wide arc. She deflected it easily, the oar glancing off her forearm as she advanced on him. "Don't want to hurt your ego or anything."

"You're going to eat those words," Emilia shot back, her muscles visibly expanding as she leaned into her cursed technique.

Furō saw her next move coming and tried to sidestep, but Emilia was faster. Her fist shot forward, her enhanced strength turning what would have been a glancing blow into a solid strike against his ribcage.

The impact was immediate and brutal. Furō staggered back, a sharp pain lancing through his chest. He felt the air leave his lungs in a gasp, and before he could recover, a wave of nausea hit him. He doubled over, clutching his side as he coughed violently, blood splattering onto the ground.

"Furō!" Emilia's voice was sharp, her sparring stance dropping as she rushed to his side. She placed a firm but careful hand on his shoulder, her expression a mixture of concern and guilt. "Are you okay? I didn't mean to—"

Furō waved her off weakly, his other hand pressed against his ribs. "It's fine. Just… caught me off guard, that's all."

"You're coughing up blood," Emilia said flatly, kneeling beside him. Her sharp blue eyes scanned him critically. "That's not 'fine.' What's going on?"

Furō wiped his mouth with the back of his hand, grimacing. The pain in his chest was fading, but the uneasy sensation lingered. "I think it's all this cursed energy. Ever since Rota, it's like my body's… rejecting it. Or maybe it's struggling to keep up."

Emilia frowned, helping him sit upright. "You think it's because of the artifacts? The bracelets, the nose ring?"

"Probably," Furō admitted. "I've gotten a lot stronger in a very short time. Maybe too strong. My body's not used to handling this much energy all at once."

Emilia nodded, her expression thoughtful. "It makes sense. You're essentially overclocking yourself. If you keep pushing like this, it's going to kill you."

"Well, that's comforting," Furō muttered, leaning back against a nearby rock. "Got any brilliant ideas, or should I just start writing my will?"

Emilia ignored his sarcasm, standing and crossing her arms as she considered their options. After a moment, her gaze sharpened, and she looked down at him. "There is one way to manage this."

"Yeah?" Furō asked, tilting his head. "What's the catch?"

"A binding vow," Emilia said simply. "You impose a limitation on yourself—something that restricts your cursed energy usage or technique. In exchange, you stabilize your power and avoid injuries."

Furō raised an eyebrow. "Like a self-imposed handicap?"

"Essentially," Emilia said. "Think of it like Nanami's Overtime Binding Vow. He limited himself to working within strict hours, which allowed him to amplify his strength when "off the clock." You'd be doing something similar, but the restriction would apply to how much of your cursed energy you can use at once."

Furō frowned, considering the idea. "So, I'd be weaker in some situations?"

"Yes," Emilia admitted. "But it would also give you more control. Right now, you're running at full capacity all the time, and it's tearing you apart. A binding vow would let you focus your power more efficiently, without overloading yourself."

He sighed, rubbing the back of his neck. "Doesn't sound fun."

"It's either that or you keep throwing up blood every time you fight," Emilia said bluntly. "Your choice."

Furō looked up at her, then glanced at the bloodstained ground. As much as he hated the idea of limiting himself, he couldn't deny the logic behind it. If he kept going at this pace, he wouldn't survive the next Valkyrie fight.

"Fine," he said finally, pushing himself to his feet. He swayed slightly, but Emilia steadied him. "I'll do it. But if I'm putting on this handicap, I want something in return."

Emilia raised an eyebrow. "What, like a bonus?"

"Exactly," Furō said, smirking. "If I'm taking a hit to my power, then when I do use my full cursed energy, it needs to hit like a freight train."

"That's how binding vows work," Emilia said, nodding. "The greater the restriction, the stronger the payoff when you break it. But the vow has to be clear and absolute. No room for loopholes."

"Got it," Furō said. He clenched his fists, feeling the toxic mist swirl faintly around his feet. "Let's get this over with."

They stood in the center of the training ground, the other sorcerers watching from a distance. Furō closed his eyes, focusing on his cursed energy as he prepared to make the vow. The bracelets on his wrists and the nose ring pulsed faintly, their power thrumming through him.

"I, Furōkawa," he said aloud, his voice steady, "hereby impose a binding vow on myself. I will limit the amount of cursed energy I can use at any given time, restricting my cursed techniques to 60% of their maximum potential."

The air around him grew heavy as the vow began to take shape. He opened his eyes, locking gazes with Emilia.

"In exchange," he continued, "when I break this vow and release my full power, my cursed energy will amplify to 130% of its usual strength for 5 minutes, but I'll take twice the damage."

The energy in the clearing surged, a visible ripple spreading outward as the binding vow solidified. Furō felt the change immediately—a faint but distinct pressure settling over his cursed energy, as though a lid had been placed over it. At the same time, he could feel the potential for a massive surge of power locked within him, waiting to be unleashed.

Emilia studied him carefully. "How do you feel?"

Furō exhaled slowly, testing the restriction. His cursed energy flowed smoothly, but it was muted, restrained. "Like I just put a limiter on a sports car. It's weird, but… it feels more stable."

"Good," Emilia said. "Now you won't collapse in the middle of a fight."

"Yeah, yeah," Furō said, waving her off. "Thanks for the lecture, Mom."

She rolled her eyes, but a faint smile tugged at her lips. "You're welcome. Now try not to break the vow unless you absolutely have to."

"No promises," Furō replied, grinning. But deep down, he felt a sense of relief. The binding vow might be a handicap, but it was also a lifeline—one he desperately needed.

As they left the clearing, Furō glanced at the sky, his smirk fading into a more thoughtful expression.

"Three more to go," he muttered as he gripped his side, "Time to play smarter, not harder."