Pinnacle of Power; Muzan is terrified.

*BANG!*

Getting hurled aside a few meters and being drenched in his sisters blood, Gyutaro, the six strongest member of the twelve Kisuki raised his head in disbelief as his pupils dilated in shock and fear.

"Sh-she's not regenerating?! You k-killed her?!"

For the first time in a millennia, the sadistic demon finally felt apprehensive, as he took a step back. The ability to regenerate almost instantly from physical attacks had enthralled him in a false confidence, and blinded him from the fact that he could truly die.

"Die!!!"

He roared out in grief and slashed out his sickles, sending out a wave of blood red energy slashes that ripped apart the building, wanting to destroy Sukuna in one move, however the king of curses disappeared from his range of vision like a ghost.

"Hehehe. Now that the distractions are out of the way, why don't we use the open space.."

Hearing a chuckle behind him, Gyutaro slashed out his sickles, however, his wrist was cleaved through by an invisible slash, and fell to the ground as blood dripped from his hand.

"Eh?"

Looking at his hand in shock, Gyutaro quickly regenerated and grabbed his blade, while Sukuna's evil laugh rang out. He swallowed in panic, and right as he was about to utilise his other blade to send out a slash, Sukuna grabbed his arm and flipped him around, before he grabbed his face and hurled him into the distance as the king of curses watched his foe disappear into the horizon, and in an instant he disappeared as well.

.

The city of Kyoto was lit, as a festival of seasons was underway, to appease the Gods, Amaterasu and Susanoo.

The men ate and drank, while the women danced and the children played with their paper dragons. All in all, the entire city was filled with sounds of joy and happiness.

However this happiness did not last for very long when a figure instantly crashed into multiple buildings like a rocket, sparking chaos in the relatively peaceful environment.

As the women and children scurried away in fear, a figure walked with his hands in his pockets like a demon God, towards the source of the chaos.

"What a disappointment. You demons with your blood demon art should be innately stronger than those demon slayers, yet they seem to outclass you in skill and strength. If not for your rengeration, I'm sure the demon slayers would've already won against you lot.."

Sukuna's words fell on Gyutaro's ears as he arose from the rubble in fury.

Looking down at his arm that was healed, he was surprised for a while, before he let out a boisterous laugh.

"It seems your attacks won't work on me after all! Let's see you be smug after I rip apart your innards!"

Gyutaro grabbed his sickles in a maddening moment and readied himself.

"You look happy, but regenerating isn't that hard for demons after all, unlike humans. Also, I can configure my own attacks to directly target the soul, and cut down the opponent in one fell swoop, like I did with your sister, or to simply cause physical damage, like in your case."

Sukuna laughed, as Gyutaro's smile slowly disappeared.

"Blood demon Art: Flying Blood sickles!!"

He immediately grabbed both sickles and slashed them out with all of his strength in quick succession, sending out waves upon waves of blood red energy slashes.

Meanwhile, Sukuna instantly moved, speeding towards Gyutaro like an arrow, seemingly disregarding all defense. However all the blood red slashes were cleaved into atoms upon reaching his body.

Sukuna hurled himself into the sky and descended with a punch that hurled the sixth upper ranked demon into another building.

Before Gyutaro could even react, Sukuna reappeared beside him and unleashed multiple kick punch combos onto his body, with every hit accompanied by invisible slashes that rend his skin, sending waves of pain coarsing through his nerves.

"Die!!!"

Gyutaro forcefully separated himself from Sukuna, rushed to a rather large chariot, grabbed it with all of his might and hurled it towards the king of curses.

Sukuna laughed and waved his fingers, turning to chariot and the massive horse into cubes of flesh and gore, as blood spilled out.

"You care so much about the humans! Then die with them!" Gyutaro screamed like a madman and hurled a mother with her two kids towards Sukuna before he slashed out with his sickles, sending waves of blood red energy that shattered once more on contact, as Sukuna grabbed the innocent mother and kids by their necks.

"What gave you the notion that I care about these pathetic worms?.."

Sukuna chuckled and right before Gyutaro's shocked expression, the king of curses chomped down on two of the kids, devouring them in an instant, as he licked the blood off his lips in ecstasy.

"No!!"

The mother cried out, as she fell to her knees, and Sukuna walked past her, only for her body to be turned into hundreds of cubes by his invisible slashes.

The next moment, every single human within a 2km radius was bisected by invisible slashes as blood rained down. In just a moment, the relatively peaceful festival had turned into a stage of bloodshed and gore.

Even an experienced demon like Gyutaro couldn't help but marvel in fear at Sukuna's actions, as he unconsciously took a step back. Without moving a finger, at least 500 humans had been killed in an instant. Gyutaro was sure that even if it were demons, Sukuna would have killed them in the same way, because someone like him did not care about those pathetic worms as he called them.

Sitting within a dojo a couple of meters away, a beautiful woman with long black hair, having pale skin and dressed in a pink kimono watched on in shock, as Sukuna ravaged the entire city without moving an inch.

"This power! I've got to have it all for myself!!"

She smashed her palm onto the ground as he canines grew out in fury.

Watching Gyutaro's shocked expression, Sukuna smugly smiled and placed his palms in his pockets.

"Don't tell me you're amazed by this little feat?"

Gyutaro picked up his sickles and instantly made a run for it, wanting to escape the cruelty of the king of curses.

"Dismantle.."

With but a command, he lost all of his lower limbs and fell to the ground. Unable to regenerate any longer, he crawled away in fear, trying to escape.

"Since you're amazed by this little feat, why don't I show you the pinnacle of all feats…"

Sukuna laughed and placed his palms together in a hand seal, as a malevolent aura slowly perfused the area.

"Domain Expansion: Malevolent Shrine.."

The last thing Gyutaro saw was Sukuna cloaked in a white and black apparel, standing before a large shrine constructed from animal and human bones above an inky black ocean that seemed to devour light itself.

His entire body was turned to dust, just like every single organism and structure within a 20km radius.

"If I hadn't escaped in time…"

Touching the wound on her cheek that refused to heal and bled profusely, the woman from before looked towards the city that had not turned into a wasteland with shock on her face. Her eyes turned to watch the figure of Sukuna standing in the middle of it all with a smirk, and just as she was about to leave, Sukuna's gaze immediately turned towards her, as she freaked out, watching those pure evil eyes watching her intently.

Without wasting anytime, she disappeared like a ghost, fleeing the place in an instant, not wanting to get caught by the king of curses.

A/N: Do you guys think I should write an Aizen ff? Like fr. I don't know what to do. The idea still weighs down on me.