Madara Uchiha In Jujutsu Kaisen

Instantly, the gritty, waterlogged subway station vanished. The scenery warped and reformed around the three sorcerers. 

One moment they were in a dark, damp tunnel; the next, they stood on a bright, sandy beach under a clear blue sky. 

Palm trees swayed gently in a warm breeze, and the turquoise ocean stretched out to the horizon. It was a tropical paradise. But they knew instantly this wasn't real. 

This was Dagon's Domain Expansion.

The peaceful illusion shattered immediately. Before Nanami or Maki could fully process the change, sharp pain erupted in their bodies. 

Strange, fish-like creatures Shikigami conjured by the Domain materialized from the air and water, biting savagely at Nanami's torso and Maki's shoulder. 

The attacks were unavoidable, guaranteed hits within the Domain's territory. The battle had restarted, but now the tables were turned. 

Inside Dagon's Domain, the sorcerers were at a severe disadvantage.

Naobito, however, remained untouched by the initial wave of fish shikigami. A faint shimmer of cursed energy surrounded him. He was using a secret technique passed down in the Zen'in clan: Falling Blossom Emotion. 

It wasn't a Domain itself, but a counter-measure, an advanced technique that allowed the user to automatically deflect or neutralize incoming attacks within a Domain by coating themselves in cursed energy, disrupting the Domain's guaranteed-hit effect. It offered protection, but it required immense skill and focus.

….

From his hidden vantage point, Madara watched the fight unfold with keen interest, analyzing the sorcerers' techniques and fighting styles. 

He saw their teamwork, Nanami's solid power, Maki's skill with her weapon, and Naobito's baffling speed. 

Then, he saw the tide turn. The cursed spirit, Dagon, getting beaten down, desperate. And then… it unleashed something new. 

A large, black sphere suddenly enveloped the entire area where the sorcerers and Dagon were fighting, cutting them off from the outside world.

Seconds passed, but the black sphere remained stable, humming faintly with power.

'Another technique,' Madara mused, his Sharingan studying the barrier. 'This feels like a barrier jutsu, maybe spatial manipulation Jutsu? Something that traps the user and their targets together, like certain sealing techniques. I can't be sure from out here. To understand it… I might have to go inside.'

He weighed his options. Intervening could reveal his presence and potentially draw unwanted attention. But it could also be an opportunity. 

These sorcerers seemed capable, and gaining their favor perhaps by saving them could be a valuable shortcut to getting the information he needed about this world and how he got here. 

After a moment's consideration, the potential benefits outweighed the risks. It was time to make an entrance.

"So, how to get in?" Madara murmured, walking up to the smooth, black surface of the sphere. He tapped it lightly with his knuckles. It felt solid, unyielding. 

"Figured it wouldn't be that fragile."

He stepped back, channeling his power. Blue energy erupted around him, forming the massive skeletal upper body of his Susanoo. 

The spectral warrior raised its enormous fists. With immense force, the Susanoo slammed both fists against the outer wall of the Domain. Cracks spiderwebbed across the black surface from the point of impact. 

The Susanoo struck again, and again, hammering relentlessly until a section of the barrier shattered inwards, creating a jagged hole leading into the Domain's interior.

Wasting no time, Madara dismissed the Susanoo and leaped gracefully through the opening, entering Dagon's world.

….

Inside the Domain:

OVERWHELMED.

That single word perfectly described the sorcerers' situation now. Outside, they had Dagon on the ropes, pushing him back with coordinated attacks. 

Inside his Domain, however, Dagon was king. The tropical environment itself seemed to empower him, and the Domain's guaranteed-hit effect made dodging the endless swarm of fish-like shikigami impossible without special defenses. The situation was completely reversed.

Dagon reveled in his newfound power, relentlessly sending wave after wave of vicious shikigami towards the three sorcerers. 

He focused the bulk of the attacks on Nanami and Naobito, recognizing them as the bigger threats. 

Nanami blocked and endured, his suit tearing under the constant assault, while Naobito used his Falling Blossom Emotion technique, cursed energy flaring around him as he deflected the unavoidable hits, though it clearly took effort.

Dagon paid less attention to Maki. Her cursed energy levels were so low compared to the others that he barely registered her as a threat within his powerful Domain. 

Deciding to eliminate the weakest link first, Dagon personally moved towards her position while his shikigami kept the men busy.

Maki was already struggling, using her polearm defensively to fend off the few shikigami Dagon had initially sent her way. She blocked bites and deflected charges, but it was getting harder to keep up.

Suddenly, Dagon appeared behind her, a cruel smirk on his monstrous face. "You're the weakest one here!" he sneered, swinging a powerful leg in a devastating kick aimed at her midsection. 

Maki reacted with incredible speed, twisting and bringing her weapon up defensively just in time. But Dagon's attack, amplified by his Domain, was far too strong. 

The impact shattered her defense, sending her flying backward like a broken doll. She crashed through several palm trees before slamming hard into the sandy ground further inland, disappearing into the foliage.

A few moments later, Maki stumbled out from the treeline, wiping blood from her mouth with the back of her hand. 

She was clearly injured, bruised and battered, but her eyes burned with defiance. She looked down at her cursed tool the sturdy polearm had been snapped cleanly in half by Dagon's kick.

"If you're going to call me weak…" she spat, grabbing the broken top half of her weapon, the part with the sharp blade still attached, "…you better kill me in one shot next time, you damn octopus!" She gripped the makeshift weapon tightly, readying herself despite her injuries.

Dagon, enraged by Maki's defiant taunt, snarled, "Then I'll grant that wish right n—" He stopped mid-sentence. The constant swarm of fish shikigami also paused their attacks.

The three sorcerers instinctively looked up, sensing a change. High above them, in the perfect, clear blue sky of the Domain, thin black lines like cracks in glass began to appear. 

They spread rapidly, and then, with a faint shattering sound, a section of the sky broke open, revealing a small, jagged hole of pure blackness leading to the outside world.

Seeing this, Nanami, Maki, and Naobito all had the same thought: Someone broke through the Domain barrier from the outside! It had to be an ally, another sorcerer arriving as backup. A cursed spirit wouldn't interfere like this. Hope surged briefly through them.

But…

What descended slowly through the hole wasn't a familiar sorcerer or a cursed spirit. It was a man clad in ancient, cracked red samurai armor. 

He had long, wild black hair, and strangest of all, they couldn't sense a single trace of cursed energy from him. 

As he floated down under the artificial sun, his eyes were closed, and a faint, almost predatory smile played on his lips, as if he was savoring the moment, anticipating the entertainment to come. 

He clearly expected something interesting here, something worth the effort of breaking in.

The three sorcerers and the Special Grade curse, Dagon, now stared up at this unexpected arrival. 

They were witnessing the entrance of someone completely unknown, an anomaly in their world Madara Uchiha, the Ghost of the Uchiha, a legend in a shinobi world, someone said to invoke fear even in demons… whose name once invoked fear across entire nations.

Madara opened his eyes mid-descent. His crimson irises, marked with three spinning tomoe the Sharingan darted around, taking in the entire scene in an instant. 

He assessed the tropical Domain, the injured sorcerers, the powerful curse, absorbing the situation in mere seconds while still suspended in the air.

'It's him!' Dagon thought, a flicker of unease running through him. 'The one Jogo and Mahito fought earlier! The one who crushed Mahito with a single punch!'

Madara also noted the bizarre nature of the Domain a completely separate space contained within that small black sphere he'd broken through. Fascinating.

Then, he vanished from the air. The sorcerers and Dagon scanned the sky, but he was gone. 

A moment later, they spotted him. 

He was standing calmly on the surface of the ocean water within the Domain, as if it were solid ground, no support needed. 

He surveyed the four figures on the beach the three sorcerers and the octopus-headed curse. Behind him, high in the sky, the jagged hole he'd created slowly sealed itself shut, the blue sky becoming seamless once more.

Dagon stared, baffled and slightly unnerved by this impossible entrance and casual display of power. "You…" he stammered, his voice loud enough for the sorcerers to hear clearly across the beach. 

"How… how did you get here?"

….

A/N: What do you think? How much time it would tale madara to kill Dagon?