The Resonance of Susanoo

Naka River Shrine, deepest underground.

This place had originally been a forbidden area used to store the ashes of the clan heads through the generations. The space was smaller than the training hall above, but the rock strata were far sturdier.

Xuan Shi stood before a blackboard, holding a piece of chalk as he drew a complex diagram of chakra flow.

"Susanoo is, in essence, the materialization of ultimate Yin Release chakra."

Xuan Shi turned and looked at Fugaku, Shisui, and Itachi before him.

"Many people believe it is a product of ocular jutsu and is inherently exclusive. But in truth, as long as the wavelength and frequency of chakra align, they can merge and amplify one another like droplets of water flowing into the sea."

"How is that possible?" Itachi frowned slightly and voiced his doubt. "Everyone's Mangekyo has unique attributes. Father's leans toward power, Shisui's leans toward genjutsu, and yours... leans more toward rules. Forcing them to merge would only cause an explosion."

"Under normal circumstances, yes."

Xuan Shi tossed away the chalk and pointed at his own eyes.

"But I have a way to make them 'behave.'"

He looked at the other two.

"Clan head, your chakra is the heaviest and most solid. You will be responsible for constructing Susanoo's 'skeleton' and ensuring the structure's stability."

"Shisui, your chakra is the most agile. You will be responsible for constructing the 'meridians' and 'armor,' granting it speed and flexibility."

"As for me..." A faint, deep-blue glow flashed in Xuan Shi's eyes. "I'll be in charge of coordination and fine-tuning, bringing all your powers together."

Ten minutes later.

The three of them stood in a triangle at the center of the open space.

Around them, thirty elite jonin who had just completed their strengthening held their breath and focused, serving as the first witnesses.

"Begin."

At Xuan Shi's command—

Buzz! Buzz! Buzz!

Three pairs of Mangekyo Sharingan opened at the same time, spinning wildly.

Boom—!!!

Three terrifying streams of chakra erupted in an instant, filling the entire underground space like a volcanic eruption.

Golden chakra surged from Fugaku and rapidly condensed into a massive skeletal frame, carrying a heavy, immovable presence like a mountain.

Green chakra surged from Shisui, turning into flowing ribbons of light that tried to coil around the golden skeleton.

Bzzzt, bzzzt, bzzzt—!

The instant the two types of chakra made contact, an intense rejection reaction occurred.

Green light and golden light ground fiercely against each other, erupting with the shrill sound of electric currents as sparks flew everywhere. The air filled with the smell of burning, as if space itself were about to be torn apart.

"Hold steady!" Fugaku growled through gritted teeth, veins bulging on his forehead.

"No good! The frequencies don't match!" Shisui felt his chakra being forced away.

Just then—

"Causal Tuning: Synchronization."

The Mangekyo patterns in Xuan Shi's eyes suddenly froze.

A deep, nearly black-blue chakra surged from his body and instantly enveloped the clashing gold and green.

This chakra did not participate in the construction. Instead, it was like a lubricant, and like a pair of invisible hands, forcibly smoothing out the edges and turbulence between the other two chakras.

The system interface began scrolling wildly:

[Chakra conflict detected... Calculating wavelength... Correcting frequency... Synchronization rate: 30%... 60%... 90%...]

A miracle occurred.

The gold and green lights that had originally rejected each other actually began to grow docile under the blue light's mediation.

The green meridians smoothly climbed onto the golden bones, growing and weaving rapidly like living vines.

Immediately afterward came muscles, skin, armor...

An unprecedented giant began to take shape within the underground space.

Its color was no longer simply gold or green, but a deep, ancient dark gold.

Though limited by the height of the underground space, this giant had only an upper body, but its size was a full circle larger than an ordinary Susanoo.

Even more terrifying was its sense of solidity.

An ordinary Susanoo looked like a semitransparent energy body, but this giant... its armor had clear metallic textures, as if it were truly existing matter.

Crack! Crack!

The surrounding barrier, reinforced ten layers deep, let out an overwhelmed groan.

Just the unconscious pressure it gave off was enough to crack the hard stone floor inch by inch.

"So strong..."

Standing at the perimeter, Itachi had no choice but to activate his own Susanoo skeleton (red) to barely withstand the aftershock and protect the clansmen behind him.

"So this is... the power after fusion?"

Itachi stared at the dark-gold giant in shock.

At that moment, the giant moved.

It slowly raised its right hand.

As Xuan Shi, Fugaku, and Shisui synchronized their movements, a spiral longsword condensed in the giant's hand.

The space around the blade distorted faintly, as if even light were being swallowed.

"Slash!"

The three of them let out a low shout at the same time.

The giant swung the greatsword, performing only a simple empty slash.

Whoosh—

An invisible sword aura instantly cut through the air and struck the rock wall directly ahead.

There was no explosion.

Only a soft "hiss."

The several-meter-thick rock wall, together with the reinforced steel plates behind it, was sliced open like tofu, leaving a mirror-smooth crack so deep its bottom could not be seen.

"Release!"

After holding on for ten seconds, Xuan Shi took the initiative to cut off the chakra supply.

The dark-gold giant slowly dispersed.

All three of them dropped to one knee at the same time, gasping for breath, sweat instantly soaking the floor.

Although it had only been a short ten seconds, that level of intense mental focus and chakra output was more exhausting than fighting for an entire day and night.

Yet in their eyes, a feverish flame was burning.

They had succeeded.

Theory had become reality.

Itachi stepped forward and looked at that bottomless sword scar, his voice trembling slightly. "The chakra density is more than five times that of an ordinary Susanoo. With this level of strength... even a Tailed Beast Bomb could be crushed in one hand."

"And this is only three people."

Xuan Shi wiped the sweat from his face and steadied himself against the wall.

He raised his head, his gaze seeming to pierce through the thick rock layers, toward the Hidden Leaf Village on the surface, toward that destined night soon to arrive.

"This is only the first phase of the experiment."

Though Xuan Shi's voice was weak, it carried a convincing power.

"When the night of the Nine-Tails' Attack comes, we will gather three hundred ninjas from the entire clan who have awakened the Sharingan."

"With this divine giant as the core, we will guide everyone's chakra and construct a defensive array on the level of a 'Thousand-Armed Kannon.'"

He looked at Fugaku and Shisui, the corner of his mouth lifting into a confident smile.

"When that time comes, Obito will discover..."

"The tailed beast weapon he is so proud of is, before us... nothing more than an oversized pet."