Naruto: My Progress in Konoha.

As the eye that reflects the soul, the Mangekyō Sharingan grants special abilities based on the user's experiences and innermost desires.

Long ago, Uchiha Haruki had often speculated—what kind of ocular power would awaken within his Mangekyō Sharingan?

Now, at last, he was about to find out.

With that thought, Haruki calmed his mind and focused inward, carefully sensing the power now residing within his Mangekyō Sharingan.

But before he could even perceive his ocular abilities, he instead detected another force altogether.

Following the feeling, Haruki guided that power outward—

—And a sudden, sharp wave of pain surged through his body.

In that instant, it felt like every cell in his body spasmed at once, twisting his face uncontrollably.

"Ugh—!"

A stifled groan escaped his lips.

In the next moment, a massive silver-white skeletal arm and ribcage materialized around him, enclosing him within.

This force was none other than the ultimate power sealed within the Mangekyō Sharingan—

Susanoo.

Susanoo is a mighty Yin Release technique obtained when one's Sharingan evolves into the Mangekyō stage, caused by a qualitative leap in spiritual energy.

It is generally divided into four stages:

Stage One:

A skeletal form envelops the user. While offering decent defense, powerful attacks can still break through.

At this level, Susanoo may wield basic weapons like swords and knives, mainly using physical attacks.

Stage Two:

The skeleton is fleshed out with muscles and clothed in a chakra armor.

At this stage, Susanoo achieves optimal balance and can utilize the universal long-range technique—Yasaka Magatama.

Stage Three:

Adds a demonic tengu-like armor, significantly increasing defense.

However, chakra consumption skyrockets, and the form becomes highly unstable—most Mangekyō users can't maintain it for long.

Stage Four (Complete Body Form):

Adds legs and a full lower body; the size increases drastically, and the user stands at Susanoo's head.

At this stage, all weaknesses are eliminated, and it gains immense mobility.

These four stages grow stronger in tandem with the user's ocular power.

As for Haruki—what he had just summoned was the initial form, separate from these stages, consisting only of a skeletal arm and ribs.

This basic version didn't fully cover his body, leaving large gaps and potential openings.

Thus, its practical utility was limited.

Aside from this form, Susanoo had a final, complete version, often called the True Susanoo.

Its size was colossal, its chakra perfectly stable. It could slice through mountains and meteors, and even had the power of flight.

Moreover, it could form seals and cast enhanced jutsu, amplifying the user's abilities to terrifying levels.

In short—it was perfect.

But to unlock this ultimate state, one must fully master the Mangekyō's power and possess enormous chakra reserves.

Haruki knew he was far from that point.

Even now, he couldn't maintain this initial skeletal form for long.

There were two main reasons:

The physical strain of using Susanoo was enormous. With his current body, he couldn't endure prolonged use.

The ocular strain was significant as well. While less damaging than casting direct ocular techniques, it still wasn't negligible.

Speaking of ocular techniques—

Haruki retracted the silver-white arm and ribs, then continued to probe the deeper powers dwelling in his Mangekyō Sharingan.

Moments later, a stream of blood-tears flowed from his left eye.

At the same time, a mysterious force erupted around him—enveloping his entire body—and he vanished from sight.

One second… two seconds… three…

Ten full seconds passed before Haruki reappeared in the same spot.

By now, that strange force had faded, but his face was a mix of shock and barely contained joy.

Why?

Because the power he just awakened was overwhelming.

At that moment, only one phrase resounded in Haruki's mind:

"Invincible."

Yes—invincible.

The ability now residing in his left eye was named:

Amatsu-no-Mikoto.

It differed by only one character from the Ōtsutsuki Kaguya's space-shifting Rinnegan ability "Amenominaka", but the effects were radically different.

In some ways, Haruki's Amatsu-no-Mikoto was even more powerful.

Its effect had two major components:

First – It removes him from this world, placing him in a state akin to "outside the three realms, beyond the five elements."

While in this state, no ninjutsu, taijutsu, genjutsu, or any other form of attack could harm him.

In fact—no one could even perceive or locate him.

Even if someone stood right in front of him, they wouldn't see or touch him.

It would be as though they existed in parallel dimensions, completely disconnected.

That alone was already astonishing.

But that wasn't what made it invincible.

Second – While removing himself from the world, Amatsu-no-Mikoto also purges all negative status effects on his body.

That was the terrifying part.

In other words, even if Haruki were struck by Kotoamatsukami, the most powerful genjutsu that could alter one's will without notice, a single activation of Amatsu-no-Mikoto would instantly restore him.

Poison?

Curses?

Missing limbs?

All gone. All reset.

Amatsu-no-Mikoto was like a system reboot or a save-point restore.

As long as he had a breath of life and a clear mind, he would never truly die.

Of course, this assumed he had enough chakra to activate the technique.

Still, it was clear—

Amatsu-no-Mikoto was utterly broken.

That's why Haruki declared it invincible.

As for why he awakened such a power, Haruki believed it stemmed from the constant life-threatening pressure he had endured.

After all, he had arrived in this world during the Third Great Ninja War, a brutal time when survival was uncertain, and his strength at the time was mediocre.

For a long time, he had lived on edge, his nerves stretched thin.

Naturally, over time, his soul developed an overwhelming desire for invincibility.

And he had always dreamed of transcending the limits of this world.

To do so, he needed unmatched strength.

Combine those two longings—and it was no surprise that such an ability had manifested.

The only regret?

Currently, Haruki could only maintain Amatsu-no-Mikoto for ten seconds at most.

Any longer, and it would place immense strain on his Mangekyō Sharingan, drastically accelerating blindness.

So even with this power, he was far from truly invincible.

He still needed to tread carefully.