A/N: They did Junpei dirty. They set him up to be a really great narrative foil to Itadori, and then they killed him off. So I decided to fix it.
Disclaimer: I haven't finished the first season, so I'm going to attribute any mistakes I make to that.
"Itadori! Itadori!" Nanami's calling his name, but it's like hearing it from the other end of a drainpipe. His vision alternates between blurry and black, and Nanami's face is closer with every blink. "Itadori." Nanami's face can't be more than ten inches away from his own, but his eyes still won't focus on it. "I'm going to take you to get medical attention."
Nanami's face disappears from his field of vision to be replaced by his shoulder. Distantly, Itadori is aware of arms around him, of being lifted off the ground, but his sluggish brain is struggling to comprehend any of it in the face of the dull pain stabbing through him.
Then an urgent thought strikes him, and he stiffens, his mind grasping onto it like a lifeline. Junpei.
"Ijichi said you two fought. What happened?"
Did I say that out loud?
"Yes."
Oh. "He's on the top floor." The voice doesn't sound like his own, all rough and slurred. "The curse...got to him." He knows Nanami will understand what that means. A salty taste reaches his tongue, and with mild surprise, he realizes he's crying.
"There's nothing we can do for him, then."
Nanami's words leave a niggling doubt in the back of Itadori's mind, but trying to grab hold of it is like trying to pull a fragment of eggshell out of an egg white, and his train of thought wanders away into nothingness.
No. Wait. His brain kicks back into gear like it's been jump started, and he flails his arms, trying to wriggle out of Nanami's grip. His feet hit the asphalt, and he takes off at a stumbling run for the nearest door back into the school. Dimly, he hears Nanami calling after him as he slams the door open and starts up the stairs, two at a time. The ragged holes through his torso are on fire, and after the first three flights, so are his lungs, but it doesn't matter, because he has to get to Junpei.
At last, he crests the top of the last flight of stairs, his traitorous chest heaving, and staggers to a halt. Blue dino-blob Junpei is still lying face-down exactly where he'd fallen minutes before. Itadori falls to his knees next to his body, searching for signs of life. The curse said he died, but maybe... He brushes Junpei's hair away from his distorted face, and-there. Under his wrinkled eyelids, Junpei's eyes roll in their sockets.
Nanami joins him at the top of the stairs, not even breathing hard. "What do you think you're doing, Itadori?"
"Bringing him back," Itadori replies without looking at him, his frowning gaze fixed on Junpei's body. "The curse said he changes the shape of a soul, right? How hard can that be to reverse?"
Nanami sighs heavily and removes his glasses to rub at the bridge of his nose. "Simply knowing how a cursed technique works does not make it possible to replicate or reverse its effects."
"But I can figure it out," Itadori insists stubbornly. "I just have to find his soul and return it to its original shape."
"Not everyone can be saved."
Itadori looks up at him for the first time, his gaze fierce. "I have to at least try."
Nanami narrows his eyes, but nods his assent. He's admittedly curious to see if Itadori can pull it off.
Itadori places both of his hands on Junpei's papery skin, his fingers spreading wide over the lumps, and closes his eyes. His cursed energy lights up in his fingertips, and he carefully inches it into Junpei, letting it illuminate his consciousness bit by bit. Tendrils of dense shadow brush up against his energy, but never long enough for him to glean any kind of meaning to them. He nudges them aside, his cursed energy casting a blue tint over them.
There. A tiny crystal, warped and stretched like taffy, emitting a soft, purple glow from its cracks. Itadori reaches out and touches it, and it shivers almost imperceptibly. He senses splitting tension in the soul, that it's been drawn out to its breaking point under the curse's influence.
Gently, he closes his fingers around it and squeezes. For a moment, nothing happens. Then, like a rubber band snapping, the tension drops out of the crystal and it molds to his hand. He releases it gingerly, terrified that he might have just made everything worse, and the crystal hardens into a new shape. It looks a lot like Itadori's own soul, but they're not exactly the same. More like a mirror image.
Itadori blinks his eyes open, his fingertips brushing leather now instead of skin, and he looks down to see Junpei lying face-down on the tile. Breath catching in his throat, he wraps his arms around the other boy's slender body and turns him over, pulling his head into his lap. Junpei doesn't stir, but his chest is rising and falling gently, and he looks exactly as he did before the curse got to him, with one crucial difference.
His hair is pink.