DXD: Naruto Recreation System

Next Day

The training ground outside the lively city was filled with noble devils, all gathered under one man.

The human who had defeated one of the strongest devils—the one known throughout the Underworld and supernatural world as the Strongest Human—stood before them with his usual unreadable expression.

His crimson Sharingan eyes scanned the gathered devils, their auras powerful yet undisciplined compared to his.

Among those present were Rias Gremory and her peerage. Beside them stood Sona Sitri and her peerage. Noble devils such as Riser Phenex, his sister Ravel, Lótia Astaroth, and Diodora Astaroth were also present.

Itachi's gaze swept over the group before he spoke.

"Where are those two?"

Rias stepped forward.

"I asked Issei to call them for training, but they were nowhere to be found. Maybe they'll come later," she answered.

Itachi nodded slightly.

"Then we will start. They'll have to bear the loss."

Without another word, he began the session with chakra training.

Itachi's voice was calm but commanding as he addressed them.

"Before we start, you must understand what chakra is."

A few devils looked intrigued. Ravel stepped forward, curiosity gleaming in her eyes.

"We devils use demonic energy, which allows us to wield almost all types of magic. Is chakra the same as magic?"

Itachi nodded but then clarified,

"It is similar, but fundamentally different. Chakra is the combination of physical energy and spiritual energy, access with precise control. Unlike your demonic power, which is drawn from your innate reserves, chakra must be cultivated through chakra pathways."

Of course, he wasn't telling them the true principles of chakra. After all, demonic energy and chakra were two completely different systems.

He raised a single hand and effortlessly formed a one-handed seal.

Instantly, the air around him shifted. A crushing pressure filled the area as the ground beneath him cracked. A visible surge of blue energy swirled around him.

Rias widened her eyes. "This… it's different from mana," she whispered, mesmerized.

It was her first time seeing chakra up close. She had seen Itachi use Tailed Beast Cloak before, but that was uncontrolled chakra, making it impossible to sense its true properties.

Sona adjusted her glasses, analyzing the energy.

"It feels… refined. Unlike magic, which fluctuates, this is stable. Even more controlled than senjutsu," she noted before glancing at Koneko, whose eyes were shining with fascination.

Itachi continued,

"Chakra allows me to enhance my physical abilities, control elements, and even wield illusions."

Some devils looked intrigued, while others remained skeptical.

At the back, Issei scratched his head.

"Sounds complicated… but if it makes me stronger, I wanna learn it!"

Ddraig's voice echoed in his mind.

["Boy, this could be useful. Chakra is different from demonic energy, so if you master it, you can use magic. I can assist in manipulating it."]

Itachi glanced at Issei and Koneko, his Sharingan glowing slightly as he analyzed them.

"Among you, I suspect only a few might be able to use it."

His eyes settled on them.

"You, Koneko… and you, Issei. With Ddraig's help, you may be able to extract some chakra."

Itachi then pass his chakra to all of them to give them feel of it. Koneko was the first one to get it.

"I already use senjutsu, and this energy is kinda similar."

She sat down, closing her eyes as she focused.

Issei clenched his fists, determination burning in his eyes.

"Alright, Ddraig, help me out here!"

Soon, the others followed.

For the next four hours, no one spoke. They were all focused on sensing and extracting chakra.

After such a long time a faint ember of chakra flickered around Issei's body, though it was unstable. Itachi observed carefully.

Surprisingly, Koneko was the next to succeed, managing to extract a small amount of chakra.

Itachi gave a nod of approval.

"Not bad. But this is only the beginning. Since most of you cannot use chakra, we will move to combat training."

Itachi turned to the group.

"Your demonic power will not help you today. Your first lesson is combat—without magic, without immortality, without teleportation. Pure skill."

A murmur ran through the crowd.

Riser scoffed.

"You expect devils to fight without our power? Ridiculous!"

Itachi didn't respond.

Instead, he vanished.

Before anyone could react, he reappeared behind Riser, striking his knee with a precise kick.

Riser stumbled, his regeneration failing to activate for some reason as his leg was dislocated.

Itachi's calm voice rang out.

"Did you forget the beating and humiliation you suffered a few days ago?"

Riser's face turned red with shame.

Ignoring him, Itachi looked at Kiba.

"Kiba, be prepared."

Kiba immediately shifted into a fighting stance and summoned his sword.

Itachi moved like a ghost, appearing before Kiba and blocking his sword with just two fingers.

Akeno teleported behind Itachi and attempted to use lightning, but before she could react, another Itachi was behind her, pressing a kunai to her throat.

The devils froze in shock.

"Your power has made you arrogant," Itachi said.

"Strength is not determined by raw power alone. True warriors master their bodies first, then their abilities."

Sona, ever the strategist, spoke up.

"So you're saying we rely too much on our magic?"

Itachi nodded and smirked slightly.

"Yes and your mental resistance is also too weak."

Diodora frowned. "What do you mean?"

Itachi's expression didn't change.

"What I mean is that you're already under my Genjutsu."

A collective gasp spread through the crowd because Both Itachi suddenly dissolved into a flock of crows, vanishing from sight.

Koneko's eyes widened in shock.

Then, the world around them shifted. Their bodies started to turn into paper. Rias' voice trembled."W-What…?"

The sky darkened, and the sun transformed into a massive eye, staring down at them ominously.

Just as panic began to set in—

The illusion shattered.

All of them collapsed onto the ground, trembling.

As they looked around in terror, Itachi was nowhere to be seen.

Then, they heard his voice.

"I'm right here."

They turned towards the sound—

And their jaws dropped.

Itachi was sitting on a chair, his legs crossed, his face bored as if nothing had happened.