A/N: Thanks for the powerstones. I'm immensely grateful.
....
Abandoned warehouse.
"Leave the warehouse," Satoru said to Mei Mei.
The curse spirit roared as its tentacles lashed out from behind it.
Swoosh!
Bang!
Bang!
The tentacles struck Satoru, but against Infinity, it proved futile.
Satoru vanished, appearing above the curse spirit, his fist descending on its head.
Boom!
A small crater was formed as a fierce gale whipped through the warehouse, sending the containers inside flying.
Satoru lightly jumped back, clenching and releasing his fist several times. 'Something isn't right...'
Roar!
The slightly injured curse spirit roared to the sky and then stared at Satoru menacingly.
Swoosh!
Purple cursed energy rapidly converged in front of its mouth and four eyes, and in the blink of an eye, it fired it!
Swoosh!
The world seemed to have lost all light and then—
Boooomm!!
A purple cursed energy sphere rapidly enlarged, swallowing not only the warehouse where Satoru and the curse spirit battled but also the nearby warehouse.
'Is this really the fight between special-grade beings?' Mei Mei thought as she stared in shock at the wide chasm where the warehouse once stood.
The culprit, the cursed spirit, still clashed with Satoru, their fists connecting with each other and creating fierce gales and spiderweb cracks that spread through the chasm.
....
In a warehouse not too far away from the battle between Satoru and the cursed spirit, a man in his late twenties stood in the shadows, calmly watching the ongoing battle.
He wore a white T-shirt with black trousers and had long blonde hair which reached his shoulders, blue eyes which shimmered, and an unsettling stitch which ran around his head.
Kenjaku, the millennium-old curse spirit; a being of both intelligence and power.
'So this is Satoru Gojo...' Kenjaku thought as he watched Satoru grab the hand of the curse spirit, spin it, and hit it on the floor.
'Such a powerful physique. Young, yet already possessing immense cursed energy and a powerful cursed technique...' Kenjaku narrowed his eyes slightly. '...perfect for a host.'
'Let's hope Rōdō doesn't destroy the body's functionality,' Kenjaku thought.
He had absolute confidence in the strength of this curse spirit created by him. Rōdō, a curse spirit he had created, embodying the hate that humans had for labor. Already a special grade from birth, Kenjaku was sure if given the time to mature, Rōdō would surpass that volcano-head curse spirit he had seen.
....
Boom!
Satoru's punch sent the curse spirit flying... again.
'I'm getting weaker,' Satoru thought as he furrowed his brow slightly. After exchanging fists with this curse spirit, he could now determine the curse spirit's cursed technique—Energy Devouring.
As Satoru kept punching it, he kept getting weaker physically, and the curse spirit's physical strength kept getting bigger.
Boom!
The curse spirit stepped forward, the ground sinking under its weight. Though some chunks of its body were missing, the pressure it radiated hadn't diminished; instead, it was much stronger than before.
Swoosh!
The curse spirit disappeared again, appearing in front of Satoru and striking with its palm.
Satoru calmly sidestepped and then struck with his elbow.
Boom!
The curse spirit doubled over, and then Satoru's kick, wrapped in violent air, struck its stomach!
Unlike before, the curse spirit just staggered back.
'As expected,' Satoru thought as he attacked again; the curse spirit's improvement hadn't surprised him.
Swoosh!
Satoru's fist streaked through the air, but the curse spirit surprisingly stepped back, letting Satoru's fist miss its face.
The curse spirit, taking advantage of Satoru's momentary lapse, attacked, its large fist whooshing through the air.
Bang!
Neither Satoru's head nor hair moved an inch as he stared at the curse spirit. 'It seems, though you keep getting stronger, you're still dumb. Haven't you noticed it yet... your attacks have no effect on me!'
Before the curse spirit could react, Satoru's hand grabbed the back of its head and brought it down, his shoulder moving upward to strike the curse spirit in its face.
The curse spirit staggered backwards. Satoru's fist struck its face, sending it to the floor.
Bang!
Watching the fallen curse spirit, Satoru slowly levitated upwards. In his opened palm was a purple cursed energy sphere.
Hollow Technique: Purple!
Satoru hurled the sphere downwards towards the still-fallen curse spirit.
Boom!!
A purple cursed energy sphere enlarged, much bigger than the cursed spirit's own, causing Mei Mei to retreat further away.
Satoru stared at the wide chasm that emitted thick black smoke for a while before scanning his surroundings, immediately noticing a slowly dispersing cursed energy in a warehouse not far away.
'Is it really Kenjaku?' Satoru thought as his lips curled slightly.
In this world, the two he was most tensed about were undoubtedly Sukuna and Kenjaku. But unlike Sukuna, whom he faced with gravity, he viewed Kenjaku like how he viewed a normal man—weak though cunning.
Just as Satoru was about to follow the cursed energy trail, something happened. From within the black smoke, thick cursed energy burst out, and then a raspy, slightly hoarse voice sounded.
"Domain Expansion: Unending Grind Mill!"
"Eh?"
Satoru's vision was soon swallowed by a bright light, and then he found himself inside the once destroyed warehouse with the curse spirit sitting in the centre.
"A domain...?" Satoru muttered as he looked around, his lips twitching slightly. A domain wasn't a simple technique; in fact, those that could deploy a domain in the Jujutsu world were incredibly few. But yet, this curse spirit had done what both sorcerers and curse spirits wished for, and it was just born not long ago!
'If left to live, rivaling Mahito, the so-called future leader of curse spirits, wouldn't be hard for this guy,' Satoru thought as he felt his body weaken and his mind move a little bit slower, but it didn't affect him that much.
"It wouldn't be fair if I don't respond in kind, don't you think?" Satoru smiled. "Domain Expansion: Unlimited Void!"
.....
Mei Mei stood at the edge of the chasm, staring at the huge black sphere with a serious gaze. Suddenly, cracks appeared on its surface, then it shattered violently, revealing another black sphere inside.
And before Mei Mei could recover from the shock, the sphere dissolved, revealing Satoru, whose clothes were still intact.
Satoru scanned the area again but didn't notice any cursed energy trail, causing him his lips to twitch.
"Guess he ran away!"
....