Test Version Blut Arterie

"Are you nervous?"

"...Yeah."

"There's no need to be nervous. Everyone came to witness your abilities."

Inside the preparation room, Sosuke Aizen looked at the somewhat uneasy Kakashi Hatake and gently patted his shoulder.

It was not the intimate gesture of patting a child on the head, but the gesture of trust between adults—a hand on the shoulder. Sosuke Aizen had never treated Kakashi Hatake as a mere child.

Feeling that trust, Kakashi Hatake's nervousness mysteriously vanished.

However, another negative emotion remained.

Fear.

With Kakashi's hearing, he could vaguely make out the noisy voices outside.

The arrangement for Blut Vene had been different. Its development had been secret, because it was something that had to be protected. The ability to defend was far more important than the ability to attack.

Blut Arterie, on the other hand, existed to announce that Konoha's offensive power had risen to a new level. Blut Vene alone had been enough to make Konoha's higher-ups float away with strategic-level misjudgments, so it was only natural that Blut Arterie would be entrusted with great expectations as well.

He did not even need to think or focus to sense the countless Ninja gathered outside. The several raised platforms seemed full of noise. Unlike those exams and missions, everyone here was a Konoha Ninja, and all of them were far more capable than he was.

Even Kakashi Hatake, who feared neither heaven nor earth, instinctively felt afraid. What if no one approved of what he had developed? What if what he had made was not good enough?

Such fears gradually tangled together into terror. He was not even seven years old yet. Listening to the noise outside, Kakashi unconsciously took a step back.

But a steady, powerful hand supported his back.

Sosuke Aizen.

This gentle man who was always smiling used his palm to block Kakashi's instinctive escape route.

"After nervousness comes fear?"

Looking at the seemingly hesitant Kakashi Hatake, Aizen smiled as he adjusted his glasses and said softly,

"Though it is a little unexpected, that truly was an action fitting for your age. It makes me very happy, Kakashi-kun."

"W-What's there to be happy about...?"

"Because you are not a lifeless object after all. You have once again developed your own hopes and thoughts about this world. You have stepped out from Sakumo-kun's shadow and become an independent person, Kakashi-kun."

"..."

"My apologies. I was a little too blunt. Let us talk about your current situation instead."

Faced with Kakashi Hatake's silence, Aizen sincerely apologized, then looked at the tightly shut door and explained softly.

"You are still afraid, but fear is essentially meaningless self-torment, Kakashi-kun. Fear cannot change anything. It is an emotion directed solely at yourself."

"But the emotions born from fear are what you need. Will you flee because you are afraid? Or will you find courage because you are afraid? That is the impact you yourself must choose to have on this world."

"Fear does not act. But whether you flee or face it, both are actions. So, Kakashi-kun, only after you act can all your thoughts and theories become real. Otherwise, they are merely delusions in your mind."

"A true person does not fear. They only obtain answers through real action. You can choose to flee and hide—for example, have me temporarily perform in your place. Or you can remain where you are and turn everyone into a joke. Finally, and most normally, you can move forward and stand beneath the sunlight."

"Go face those who once doubted you, those who once slandered you. Wield your Blut Arterie and strike them hard. Tell them who you are. I think that answer suits you better."

"..."

It was Aizen's characteristic style of comfort, as always.

It was filled with a forceful arrogance, and mercy built upon that arrogance.

Yet strangely, it gave him a sense of reassurance. As though he could find happiness by entrusting everything to him.

Kakashi Hatake slowly closed his eyes and began to review every little moment he had spent living in Aizen's home over the past few months.

In truth, Blut Arterie was definitely not something as simple as a theory in Aizen's hands. What had truly been handed to Kakashi was a scroll containing a simplified, completed Blut Vene, along with several technical concepts for performing Blut Arterie.

Though Blut Arterie and Blut Vene sounded like corresponding terms on the surface, they were fundamentally not the same thing at all.

Blut Vene completely used Chakra's own energy to create imprints, coordinating all of one's power with the outside world before condensing it into a shield upon the skin.

Blut Arterie, however, completely used external energy to strengthen one's own power, enhancing and unleashing the might of one's Ninjutsu and Taijutsu by several times over. It could be said that this was an extremely dangerous thing.

For some unknown reason, once the energy capable of driving internal and external interaction entered the body, it would turn the person into a stone statue and mutate their flesh. It was extremely dangerous to the human body, difficult to observe and understand, and always remained in a violent, furious state.

Aizen had proposed several methods of isolation and extraction, but as for how to use this omnipresent yet exceptionally violent external energy, he only had a few rough ideas. After ruling out a series of dangerous modifications related to the body, Kakashi ultimately chose an approach similar to Blut Vene.

By applying sensing fluid and markings to the surface of the body, using the internal vein map provided by the Byakugan Clan, the Hyuga Clan, he transformed the Chakra within the body into designated external and internal routes. After intertwining the veins one to one, he formed a state called the 'Perfect Sage Body,' which could synchronously siphon external energy while maintaining a balance with the energy within his body.

In this state, the body's vitality would increase dramatically, all five senses would rise sharply, and the power of Taijutsu and Ninjutsu would nearly double.

But the price was that once he suffered a powerful impact or injury, the Perfect Sage Body connection would immediately break, returning him to a normal state.

To Kakashi, this Blut Arterie was undoubtedly inadequate, but the Third Hokage believed it was all excellent.

After all, in a three-man squad, one person could take the front line with Blut Vene, another could provide offense with Blut Arterie from the rear, while a Medical Ninja watched over them in the middle. Was that not perfect?

Though it did not meet many of his own requirements, if it was merely brought out for a trial, it was already enough to hand in a satisfactory answer for many people.

That was right. There was nothing to fear.

The theory had already been verified. Combined with the special sensing potion Aizen had provided and the emergency mechanisms, there was no possibility of failure.

Kakashi Hatake slowly opened his eyes. The noise outside returned to his ears once more. But this time, those clamor-filled voices had changed from imagined doubt and anger into voices of support and understanding.

"I'm going, Aizen. Watch me."

"I look forward to your performance, Kakashi-kun."

Watching the small figure push open the doors, Sosuke Aizen adjusted his glasses and remained where he was, still wearing a gentle smile.

There was no need for introductions. Everyone had been waiting for a long time. As the acknowledged Jonin most capable of taking a beating, Jiraiya had already struck a bold pose, joking and bantering with the Ninja watching from the platforms.

But when he saw Kakashi emerge from the corridor, the frivolous expression on Jiraiya's face faded. Looking at Kakashi Hatake, who silently pulled out a vial of liquid, he could not help saying,

"You're Kakashi Hatake, right? You really don't need to hold back. I've already prepared Blut Vene and some padding. Just come up and attack. You're only a Chunin. I'll spar with you and help demonstrate it. There won't be any problem."

"..."

Ignoring Jiraiya, Kakashi silently poured the vial of reagent over his head.

Feeling a cool sensation spread from his hair through the area around his skull, Kakashi stood in place.

He closed his eyes and clapped his hands together.

A crisp smack rang out.

"Blut Arterie: Perfect Sage Body!"

The liquid provided by Aizen flowed from Kakashi's forehead toward both sides, solidifying in the blink of an eye into two pitch-black markings above his brows.

Driven by a strange siphoning force, the vein-like patterns gradually turned red and instantly surged along the paths of his veins into Kakashi's limbs and bones.

After no more than a second, Kakashi Hatake slowly opened his eyes. In that instant, his pure black eyes met Jiraiya's, who was too shocked to control himself.

"One."

The next second, Kakashi Hatake vanished from Jiraiya's sight.

First came the impact on his shoulder, a ferocious blow no weaker than one from a Taijutsu Jonin. Only then came the muffled boom.

A violent gale instantly swept across the spectator platform behind Jiraiya, scattering the various snacks held by the Ninja watching the spectacle into a complete mess.

But no one had time to care about that now.

Looking at the defense of his Blut Vene, which had nearly been overwhelmed, Jiraiya stared uncertainly at Kakashi, who stood before him in a kicking stance, faint arcs of lightning flickering around his brows.

Faced with the alternating light and dark markings on Kakashi's body, his shining veins, the imprint upon his brow, and the energy surging around him as though it were breathing, Jiraiya felt as though he had witnessed an unbelievable miracle and could not help shouting,

"This isn't Blut Arterie. This is Sage Art!"

"A brand-new Sage Art!"