With Mangekyo, I Escaped Konoha To Other Worlds [Naruto/AttackOnTitan]

Hey Guys. Sorry for dragging this out this Long. For those who feel like it, It was not my intent to make it feel like filler. It's simply Buildup for better Character development. Both main character and side Character alike.

I can't help myself sometimes.

Fortunately, this is the end of the Fight arc, with the next chapter Transitioning to other topics.

Please note that I am not making another edgy MC. Majority of all this is just deliberate acting. Let me know if the MC starts getting too edgy when he's not pretending and even when he is. The last thing I want is to create a forced, cliche plot.

Anyway, enjoy.

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Garrison Square – Trost District

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The Garrison Square was a battlefield.

A massacre.

A one-sided display of absolute domination.

Seiji moved like a blur, his movements weaving through the battlefield in a deadly dance. Every strike he made sent soldiers sprawling, their bodies twisting unnaturally from the force of his blows. Some were flung backward, colliding into others like ragdolls, while others crumpled to the ground, clutching broken ribs.

A soldier swung his sword at him from behind. Seiji sidestepped effortlessly, his hand catching the blade midair. With a flick of his wrist, the sword was wrenched away, spinning through the air before embedding itself into another soldier's shoulder.

He jumped, using one soldier's head as a platform, pushing off to launch himself toward another cluster of men. Midair, his leg shot out, slamming into the nearest opponent's chest, sending him flying into the others like a wrecking ball.

The screams and pained grunts of the soldiers filled the air.

But none of it slowed him down.

He landed amidst three men, twisting to deliver a vicious kick to the first. The impact sent the man sprawling, his head bouncing off the cobblestone. The second soldier barely had time to react before Seiji's elbow buried itself into his sternum, forcing the air from his lungs in a choking gasp. The third had enough sense to raise his weapon, but Seiji caught his wrist and twisted—SNAP—before flipping him over his shoulder and slamming him into the pavement.

He was untouchable.

From a distance, Rico Brzenska and Ian Dietrich stood frozen, their hands clenched at their sides as they watched the one-sided slaughter unfold.

"Is this… is this still human?"

A soldier at the backline spoke. His voice was barely above a whisper as watched from what he considered a safe distance, eyes wide in horror.

Another swallowed hard. "At this rate, he'll take out the entire Garrison."

"This can't be happening."

"The priests were right… demons do exist."

"…. He's a Titan in human skin."

The words sent a shiver down Rico's spine.

Ian Dietrich stood beside her, his face pale, his hands gripping his Maneuver Gear.

"Squad Captains, what are your orders!" A soldier's desperate cry snapped them back to the present.

Ian hesitated, eyes darting between the bodies piling up around the square. How… how do we stop this?

"Captain, do something. At this rate, he'll take out the entire Garrison if we don't!"

The sound of grunts in the distance was still loud.

'Just who is this guy?'

Ian clenched his fists. "Right! Let's use our ODM gear—"

"No." Rico cut in sharply. "There are too many people."

Seiji was in the thick of the Garrison forces. If they launched an all-out attack using ODM gear, they risked killing their men in the chaos.

Ian faltered. "Then what do we—"

"We beat him with what we're best at." she replied. Following which …

"Everyone, fall back!" Her voice rang loud and clear. "Get away from him! NOW!"

In the same moment, her ODM gear fired a cable to the opposite building at the end of the square.

For the Squad Leader's words, there was no argument. The surviving soldiers immediately turned, abandoning the fight as they fled in all directions, desperate to escape.

For the first time since the battle began, Seiji halted his attack.

"Now!"

She launched forward, the reeling function kicked in, pulling her forward at breakneck speed.

Seiji's eyes flicked to her position, noting her rapid approach.

'I got you now.' Rico's grip tightened on her blade.

She swung.

The steel sliced through the air, aimed directly at his neck—

But he moved.

Not by turning or shifting naturally, but with an unnatural, precise dodge, like he had foreseen the attack itself.

Rico's eyes widened in horror. 'I… I missed?'

She landed on the opposite side of the square, immediately turning back to face him, expecting a counterattack.

But Seiji didn't move.

Instead, his gaze dropped to his left shoulder.

Blood dripped.

Rico followed his line of sight, then looked at the blade in her hand.

Red.

His blood.

For a moment, silence reigned.

Seiji slowly lifted his hand, fingers brushing against the wound. Then, he pulled his palm away and examined the crimson streak staining his skin.

His face darkened considerably.

"I see." His voice was dry, almost devoid of emotion. "I underestimated you."

His gaze flickered with calculation.

Rico had moved faster than expected. His Sharingan had tracked her approach, but his mistake had been assuming his speed was enough to counter her mid-swing. The Body Flicker Technique wasn't instant—it had a split-second delay. That fraction of time had cost him.

He had beaten so many soldiers here that for a moment, he had forgotten his name wasn't Madara Uchiha, Shishui Uchiha or Namikaze Minato.

Had he dodged from the start, he wouldn't have been hit. But he had chosen to counterattack instead, expecting to end it in one move.

In his view, defeating a soldier mid-ODM utilization would do the finishing job. Bringing the shock and horror to the needed peak.

Then, he would stop here and leave. Waiting for Erwin and the Survey corps to do the followup in the next step of his plan.

It was all perfect. However …

Thinking of this, Seiji's expression darkened even further.

Not just because he, a Transmigrator, movie and novel lover, had unknowingly done a classic of despising the enemy, but also because …

"See that?!" Rico shouted. "He's not a demon! He still bleeds!"

"…" The silence lasted for a second.

Then, a soldier echoed her words. "Yeah… that's right."

Another voice joined. "Even Titans bleed! We have our gear! There's so many of us! We can take him!"

"Let's cut him down!"

The atmosphere shifted. Morale was a peculiar thing. In a world where people knew they might have to sacrifice their lives at any moment, it would have quite amazing effects.

The fear Seiji had cultivated—the terror he had instilled—was unraveling.

As that single happening alone had brought all his actions undone.

"… I see."

In that instant, his Sharingan spun—

The double Tomoe instantly moved a step further. A third tomoe appearing in his eyesight. A point that went unnoticed to all of them.

"… Very well then." He had been using a double Tomoe Sharingan all this while.

At that moment, a dozen Garrison soldiers fired their cables and shot forward, blades raised.

Seiji exhaled. 'Perhaps it's time to be a bit more heavy-handed.'

In his plan, it was imperative to achieve an overwhelming dominance here.

With this happening, leaving now would be counterproductive.

In that case, he had to start all over again.

His hands blurred.

Alongside a puff of smoke.

"Summoning Jutsu, Lightning Flash blade creation 口寄せ・雷光剣化­ (Kuchiyose: Raikō Kenka)."

A dozen shuriken emerged, flung in a precise arc.

Each one struck true—cutting ODM cables, jamming gears, slicing into wrists.

The results were immediate.

Some soldiers crashed to the ground as their lines were severed. Others lost control mid-flight as their ODM gear malfunctioned. Several simply cried out in pain as their wrists were pierced, throwing off their balance.

The coordinated attack collapsed in an instant.

Rico's breath caught. 'No…'

"Don't stop. Keep—"

She never finished.

Seiji was already moving.

In one fluid motion, he pulled out four kunai, each wrapped with paper bombs, and hurled them in the four cardinal directions—attaching them to walls, pillars, and the ground.

A moment of silence.

Then—

Four simultaneous explosions rocked the square.

Flames and smoke swallowed the battlefield.

And in the chaos, Seiji struck.

One by one, bodies fell. Garrison soldiers screamed, their attacks broken.

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Trost Hospital

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Pixis and Erwin were preparing to depart when the explosions rang out.

They turned sharply. From the distance, they could see smoke rising into the sky.

"… good god."

Not far away, a civilian saw the scene, his eyes widening.

"… Do you guys see that."

"Is that … The Garrison Building?"

"I see it."

"What happened."

Hearing the discussion of the civilians, Erwin's eyes narrowed.

Without hesitation, he pulled on his reins.

The horse rode off.

Seeing this, Pixis did the same.

"Hyah." The group of high-ranking soldiers rushed towards the chaos in The Garrison.

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Garrison Branch HQ, Garrison Square

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Post-Battle Aftermath

The air was thick with dust and the acrid scent of burning wood. The once-proud Garrison training grounds had been reduced to a battlefield. Scattered across the stone-paved yard, bodies lay motionless—some groaning in pain, others unconscious, while a few had already fled in sheer terror.

"… He …"

"… What kind of monster is he?"

A last group remained—small, battered, and barely standing—huddled together. Their legs shook, hands clenched around their weapons, though none dared to raise them.

The memory of what they had just witnessed still burned fresh in their minds.

Their eyes were drawn, unwillingly, to the boy who stood at the center of it all.

Seiji.

His Sharingan, three tomoe spinning lazily in each eye, gleamed in the moonlight. He looked like a specter in human skin—no, not a specter.

A Titan in human form.

Never had that phrase been so fitting.

Ian swallowed hard, his Adam's apple bobbing. His fingers trembled slightly as they gripped his sword's hilt.

Most shifted uneasily, while another soldier subtly edged backward as if contemplating escape.

Yet despite their fear, none of them ran.

Unlike the others who had abandoned their posts, they stood their ground, even if it was only barely.

For a long moment, there was only silence.

Just when it reached a suffocating height …

"I've had enough."

The tension was cut with a single sentence.

Then, slowly, Seiji's crimson eyes dulled, fading back to black as he exhaled. Without another word, he turned on his heel.

The group still didn't understand, until they saw him walking into the distance.

He was leaving?

The group was stunned.

They had mentally prepared for another attack, for more brutality, for something—anything. But instead, he was walking away?

A few of them exchanged uncertain glances.

"Is he … Leaving?"

The person they thought was going to murder them was walking away.

As they watched him walk away, some felt relieved. Others confused.

Yet nobody spoke. All simultaneously wanting this nightmare to end as soon as possible.

It should have. But then—

"Hey!"

The sharp call shattered the silence.

Everyone froze.

Rico had stepped forward, her face set with determination.

"Rico… what are you—" Dietrich began, only for her to cut him off with a raised hand.

She didn't hesitate. "Hey! I'm talking to you!" she yelled, her voice unwavering.

Seiji's footsteps paused.

A cold, heavy feeling settled in the pit of everyone's stomachs.

'Damn it! The squad captain is going to get us all killed.'

That was the collective thought.

Slowly, the boy turned his head, his side profile visible.

"… What?"

Rico clenched her fists. "Why?" she demanded. "Who are you? You invade our Garrison and attack us without reason. And then just leave? What grudge do you have against us?"

The silence stretched.

Then—

"The slight trembling of your hands shows you're afraid," Seiji observed, turning to face her fully.

Rico's breath caught.

"And yet," he continued, tilting his head slightly, "you still have the courage to speak."

His gaze sharpened, analyzing her.

"I wonder where it comes from… Or do you think I won't kill you because I haven't killed anyone else?"

Her blood ran cold.

'He… he didn't kill anyone?'

Ian Dietrich's expression shifted to disbelief. His eyes darted across the battlefield—bodies strewn across the ground, soldiers barely conscious but alive.

Alive.

During the chaos, none of them had been able to track Seiji's movements clearly. But now, looking back, Rico realized it.

He could have killed them all. Easily.

But he didn't.

At least, his attacks so far hadn't evolved beyond punches and kicks, while there was still a sword strapped to his waist.

If that was the case, then… then what was his purpose?

Realizing this, and seeing he had seemingly lost interest in them, the blonde decided to take a risk. Interrogate him, and see if she can dig up any useful information.

At the very least, what had happened today wouldn't be in vain.

Seiji could immediately guess her train of thought, and pointed it out directly.

The woman trembled even more. Nevertheless, she didn't back down.

If she died today, then so be it.

Her lips parted slightly, steadying herself.

"I just … I want to know why," she said, her voice quieter now. "From a logical standpoint, it makes no sense. Who are you, and why are you here?"

Seiji chuckled, amusement flickering in his dark eyes.

"Alright," he said. "I'll humor you."

In fact, this was precisely what he was waiting for.

Originally if no one asked, he decided to settle for dropping a cryptic one-liner before disappearing.

Now, he could extend that one-liner to a full dialogue.

Since she wanted to assist, Seiji had no reason to refuse.

If not, he would have simply flickered away without another word.

"I didn't kill any of you because your lives mean nothing to me."

The answer was cold. Unfeeling.

Rico stiffened, but Seiji continued.

"I have no interest in your people living within the walls. My purpose, is to find the Titan shifters."

Titan shifters?

The words struck everyone like a bolt of lightning.

Rico's mind raced. 'He mentioned before that he was looking for intel on the Armored and Colossal Titan. So… he's talking about them?'

Ian spoke up then, the squad captain finding his voice. "T-Titan shifters? You mean you're here to find the Armored and Colossal Titans?"

"Yes." Seiji's answer was blunt. "However, now I've changed my mind. Your archives don't contain anything useful about Titans—much less Titan shifters. It'll be a waste of my time to stay and investigate further. So I'm leaving Wall Rose."

His gaze flicked over them once more, then he turned away.

"The Colossal Titan has already destroyed one of your walls," he continued. "It won't be long before it reappears to destroy the second. I just have to wait until then."

His words sent a ripple of shock through the group.

"In that case, we should meet again. Or not. It depends on if you can live that long."

In saying that, Seiji turned around and took a step before disappearing.

Using body flicker to the utmost, he disappeared from The Garrison in the blink of an eye.

Leaving behind a large number of unconscious In the Branch HQ.

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Seiji's POV

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'… That should be enough'.

The young Uchiha thought as he made his way to Wall Rose.

In due time, he, Seiji Uchiha would have to interact with the people of this world. Of course, when that happened, it would be on his terms, free of all form of coercion.

If all went well, then that day was coming soon. Not too long. At worst, a week. And at best, Tomorrow.

It all depended on how fast Erwin would react to his presence.

At that moment, Seiji's eyes caught something. Speak of the devil and he will appear.

In the distance, riding on the streets of Trost were Erwin, Hange, Pixis and the others.

From the looks of it, they were returning from the hospital, most likely due to the ruckus at The Garrison.

One riding below and one leaping above. One not noticing and the other keenly observing.

Both sides passed each other, Erwin Smith being none the wiser.

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Trost District Hospital

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Inside the hospital, In a certain ward, Ilse Langnar opened her eyes.