~Flashback~
"I'm a genius."

Running through the halls of the Zenin clan's household was a young boy with pitch black hair as his sharp brown eyes held excitement with them. He wore the traditional black shitagi, a kosode, along with a white hakama. As he ran through the halls, the child known as Naoya was thinking to himself with a smile on his face.

"Everyone told me i'll be the next clan head, succeeding my father, but there is also a failure in the Zenin clan. A man that doesn't have an ounce of cursed energy. I wonder how disheartened he will be, I wonder what sort of miserable face he will have."

This wasn't the look of a disheartened man. He didn't even look miserable like Naoya thought he would. This man radiated something ominous, he sent goosebumps through Naoya's entire being. He wanted to look away before the man could notice his state. His mind told him to run away, yet his legs were frozen stiff. For the first time in his life, Naoya recognized true strength and feared it just as much as he idolized it.

~Flashback ends~

"Why?"

A loud crash was heard as various parts of the Zenin household's walls were crumbling apart. Naoya was currently on the ground as he was having difficulty breathing after Shiki punched him in the gut. While the Zenin head was slowly getting up, he couldn't believe what he was experiencing.

"Why is this feeling I have facing against a mere Nanaya....the same as when I first met Toji?!"

"Did you think I would let you catch your breath?"

Suddenly the Zenin head heard the sound of bones cracking as Shiki delivered a powerful kick into his chest. As he crashed through a wall, Naoya was still having difficulty getting back up. The feeling he had while fighting Shiki was similar to when he met Toji, but there was a difference. With Toji, Naoya's instincts told him to run yet his fear is what kept him from moving.

With Shiki, it was different. His body had chills when fighting the executioner, but the drastic difference was that Naoya could keep moving. He could still fight back against the boy, yet somewhere deep within Naoya's mind was severe doubt. Was he calm because he had a chance of victory or was it something else entirely?

"Oi, quite holding back on me. I know you have it. You're the one who took Asuramaru away from me, so clearly you have it! Why aren't you using it?!"

"Naoya, don't you remember? Asuramaru has great amounts of cursed energy. Even if I lack any, you would've sensed me arriving at your headquarters if I brought it along."

".....wait a minute. If you're not using Asuramaru then that means you've been killing everyone with-"

"With a regular katana, I effectively have been slaughtering your clan. With my Mystic Eyes of Death Perception, even if I kill you without cursed energy, you have no means of ever returning back to life even as a cursed spirit."

The sound of his own heart beating was echoing loudly in Naoya's ears. This boy, who was struggling to fight him when they first met has managed to slaughter his brethren without even using the cursed treasure he possessed. He couldn't accept this, he wouldn't accept this. Naoya refused to ever acknowledge someone like Shiki.

"No cursed energy, no magic. Yet you don't despair. What the fuck is wrong with you? STOP TRYING TO IMITATE HIM, YOU FAKE!"

With a loud scream, Naoya was suddenly in front of Shiki as he began to launch a barrage of punches at the boy with tremendous speed. However, Shiki wasn't the least bit fazed as he effortlessly kept blocking each and every one of Naoya's attacks with his bare hands. Suddenly, Naoya grabbed a hold of Shiki's left arm as the boy was suddenly frozen inside an animated frame before the Zenin suddenly kick him through a wall as the two of them were now outside of the household.

"You are not, Toji-kun. You will NEVER be Toji-kun."

As Naoya saw Shiki's body free from the frame, he suddenly grabbed a hold of Shiki's legs and was repeatedly slamming his body onto the ground. But each time he tried, Shiki always landed on the palm of his hands with a bored expression on his face. Soon Naoya threw the boy at a nearby tree as he began to repeatedly stack his cursed technique onto himself in order to increase his speed. Suddenly the Zenin was right in front of Shiki as he held back his right fist.

"The sin of small fry is not understanding true strength. Maybe that's why nobody understood Toji-kun. If you succeed in this mission, it's proof that you might be the same as him. That you could be able to understand him. That everyone acknowledges that you surpassed the Zenin! I refuse to accept that!"

Just as Naoya slammed his right fist into Shiki's gut, he could see it. In that brief moment, Naoya Zenin had surpassed his limit. The moment that confirmed it was a flash of cursed energy that turned pitch black. His only thoughts at the moment were how to crush the man named Shiki. However, what he witnessed next shocked him even more. Even though he got hit directly in the gut with a Black Flash, the katana wielding assassin somehow managed to tank the hit with minimal damage to him.

"Is this all that your pride as a Zenin amounts to? If so, it's a miracle you guys didn't die off sooner."

"A simple fluke like that won't work on me!!!"

Once more, the black sparks appeared the moment Naoya struck Shiki's chest. Four trees behind Shiki broke apart from Naoya's attacks yet the boy still stood strong as he took the hit!  While Shiki stared blankly at Naoya, he wondered why the Zenin was so hell bent on using the same attack again.

However, there was another benefit to Naoya performing Black Flash. It was the fact that by landing even one greatly increases performance in combat, allowing a sorcerer to fight at 120%. Though as powerful as the phenomenon is, no one can use Black Flash at will. However, in the case of Naoya Zenin in this very moment, one could say he was loved by the black sparks.

Soon the Zenin's leader dashed around as his speed was growing more and more. He clenched his right fist tightly, ready to land one more attack. He wasn't going to let the Zenin clan die like dogs, not to someone like Shiki. Just as he built up enough momentum, Naoya was now in front of Shiki as his right fist was inches away from the boy's solar plexus as he saw that he had Shiki up against an outside wall of the Zenin clan's hideout.

"The one who stays standing will be the strongest. I won't lose to some powerless brat who has less than a year's worth of experience as an executioner!"

The wall behind Shiki cracked instantaneously as sparks of black crackled through the air. Naoya smirked knowing that his right fist felt flesh upon it. Yet something felt off about this situation. Shiki wasn't gasping for air, neither did Naoya feel any kind of blood on his hand. Instead, he felt a tight grip upon his fist as he heard the sound of bones cracking. As the debris was falling from the broken wall and the dust finally settled, Naoya's eyes widen with horror with what he witnessed.

"What's wrong Naoya? Surely a clan head can handle a nobody like me, right?"

"No way.......he caught it? He CAUGHT my fist just as the Black Flash landed with his bare hand! He tanked the first two and then caught this one! What the hell is up with his body?!"

"Knowing you, you were probably thinking of killing me just because of shit like pride, right? Don't romanticize killing someone. Instead of thinking of your pride, you should've thought about how to survive. Now you're gonna die without a single ounce of the pride that you cared so much about."

It all happened in a flash, suddenly Shiki dashed around Naoya as he clenched his right fist tightly. Just as the Zenin turned around, he found it difficult to breath as Shiki slammed his right fist into his solar plexus. Before he knew it, Naoya found himself being blasted through several walls of the Zenin Clan's household. Two walls became four. Four became eight. Eight became ten. One after another, Naoya's body was crashing through several walls until it hit a tree on the eastern most part of the household.

"We were in the west wing when I launched those Black Flashes.....yet one attack from him, sent me all the way to the east wing?! His punch did more damage than a Black Flash?!"

He couldn't breath properly, the bones in his body were starting to shatter as blood escaped his lips. As his vision was getting blurry, Naoya could hear the sound of footsteps slowly getting louder and louder. Slightly lifting his head, his eyes couldn't hide their horror when he saw Shiki heading towards him without a single sign of damage that would impede him.

Soon Naoya began to realize something. The reason he was still able to move and fight against Shiki wasn't because he was confident he had a chance, but rather it was the exact opposite. The only reason he was allowed to fight back, was because his mind instantly realized that Naoya would die even if he decided to run away. The reason he was fighting, was to not make his death look as pathetic.

"Is this it .......I trained many years to get this position. I even betrayed my own father and had that old fuck killed just to become the family head! I was willing to take his place and prove that the Zenin clan deserves to be at. The top of the organization! You're telling me the one who is taking all of that away from me is some powerless kid?! No! I REFUSE TO FUCKING ACCEPT THAT!!"

"Heh. Hehehehehe! Hahahahahahahaha!! Talking down on me so early? YOU REALLY AREN'T FIT FOR THIS WORLD, YOU GODDAMN BRAT! IF YOU'RE GONNA LOOK DOWN ON ME, DO IT WHEN YOU ACTUALLY MANAGE TO KILL ME! THE ONE WHO DESERVES TO BE ACKNOWLEDGED BY TOJI-KUN, THE ONE WHO DESERVES TO BE ONE OF THE STRONGEST, THE ONE WHO DESERVES TO STAND ON TOP IS ME!"

He couldn't move his entire body after that last punch he took from Shiki. It was a miracle that he was still alive. The one thing that kept Naoya from giving up was his absolute hatred for the boy walking towards him. His pride as a Zenin, the status that he finally obtained, his chance to prove that he was a better fit as head than his father, he refused to let some random kid take all of that away from him and make his sacrifices be worth nothing. As he brought his hands together, Naoya began to smirk as he looked at the boy before him

Before he realized it, Shiki was now inside of a pitch black area that had a straight path made of flesh heading towards the center. At the center was none other than Naoya Zenin as a large eye was seen directly behind him. This was it, this was the apex of Naoya's cursed technique.

"Anyone who moves within the domain must abide by the 24FPS rule of Projection Sorcery or they will receive numerous injuries. The domain increases the precision of the embedded cursed technique and targets individual cells. Freezing individual cells disrupts them and causes countless small cuts and gashes to appear all over the body, completely immobilizing any target. Forcing a movement can cause an appendage to be cut off completely! Of course by revealing all this via binding vow,y technique is more effective! What will you do now, Shi-"

"You really think a Domain Expansion is enough to kill me?"

The moment Naoya blinked, Shiki was already in front of him with his right hand resting on the hilt of his katana. While Naoya was confused as to why Shiki wasn't effected by the sure-hit effect of his Domain Expansion, Shiki merely looked at Naoya like one would look at garbage littered all over the ground.

For people like Toji and Shiki who lack cursed energy, barrier techniques categorize them the same as structures or buildings. Unless the barrier uses a physical object as its shell, they agree to the conditions, or they willingly choose to invade it .......Toji or Shiki can't be trapped inside of a domain and the sure-hit effect of a domain has no way to recognize them as a target.

But in the case of Koritsu Shiki, he stayed within the domain for one reason only. To destroy everything Naoya about him. His strength, his cursed technique, his pride. Koritsu Shiki's objective was to kill everything that made up the existence known as Naoya Zenin.

"Allow me to show it to you, Naoya. Your Domain Expansion, your pride, your life. I'll expose how fragile they are with just this one slash."

As Shiki took a stance, Naoya's entire body began to shake uncontrollablly. The once calm executioner was now releasing an unmeasurable amount of bloodlust. The moment he looked at Shiki, he felt as if his eyes were playing tricks on him. Because for a split second, Naoya thought he saw the impossible. He thought he saw a man.......

.....even more terrifying than Toji Fushiguro.

"Flashing Scabbard:Domain Severance."

The apex of the Nanaya Clan's swordsmanship is about to be revealed.