I Returned with the Cheat Holy Sword

Riding atop a massive creature isn’t exactly something you get to experience often.
Even Carlyle, who had repeated countless regressions, had only done this once before.
In fact, the reason he’d failed to tame the Black Mirror Beast in that previous timeline had been simple.

Thanks to the presence of the world’s strongest force—Miss Hero herself—it had been possible to subdue it. But using it as a mount? That had been another matter entirely. The thing had acted far too violently for that.
I’d rather die than let anyone ride on my back. That was the default attitude of the Black Mirror Beast.
And now, Carlyle and his group, standing directly atop it, could feel it clearly for themselves.

An aura of black mana, incomparable to the earlier approach, surged in all directions.
What should he call it? Earlier, it had felt more like a defensive burst, trying to keep them at bay—now it was clearly laced with murderous intent, thick and suffocating in the air around them.
Apparently sharing the same impression, Panhyma shouted at Carlyle while helping a staggering Vespa keep her balance.

“Was this really a good idea?!”
“Yes.”
“⋯⋯.”

Panhyma stared at him, dumbfounded by the curt reply.
But he was being sincere.
Having once ridden atop the Black Mirror Beast while it was still in its right mind, Carlyle was sure of one thing.

—As I thought.
If the Black Mirror Beast were truly trying to kill them, this wouldn’t be it.
This wasn’t a calculated attack.

It was much closer to a panic-induced frenzy.
This beast wasn’t capable of rational thought right now.
[...Wait. Isn’t that strange?]
Pardon?

[You said the beast has no emotions—only instinct. But the way you’re talking about it now...
...it sounds like you’re describing a sentient being with feelings.]
Like he was talking about a person.
I used to think the same as you, Miss Hero.

Carlyle had once held exactly the same belief Gray was expressing now.
If it hadn’t been for that one myth Panhyma shared with him, he probably still would.
How should he put it?

The story had recorded behaviors that couldn’t exist without some form of interaction with the Black Mirror Beast.
Not as an emotionless animal ruled by instinct—
But as a being with intelligence, capable of dialogue, and—most importantly—capable of feeling.
What he was about to attempt now was based entirely on the assumption that this was true.

“Comrade! We need to act—fast!”
Even ◈ Nоvеlіgһт ◈ (Continue reading) as those thoughts passed through his mind, the rising tide of dark mana made Panhyma shout again.
Instead of replying, Carlyle simply crouched down.

“Just a moment.”
Diagnosis came first.
He placed his hand on the Black Mirror Beast’s massive head.

The Holy Sword, transformed into pure mana inside his body, flowed outward through his hand as he made contact.
And in that moment—
—a revolting sensation surged through his entire body.

“⋯⋯.”
Carlyle recoiled as if he'd just plunged his hand into molten lava.
That was enough.

The Holy Sword, inherently opposed to all energy from Hell, produced this exact reaction when touching something tainted deep inside.
The sulfuric stench.
The death energy of a demon.
It’s been brainwashed.

[Brainwashed?]
Those bastards either threatened it, or abducted one of its kin... and forced the memory into it.
That meant the Black Mirror Beast’s destructive rampage wasn’t about attacking an enemy.

It was simply reacting in terror to implanted fears.
It believed its family was in danger.
[Then... what do you plan to do?]

I mean, we’re the so-called Hero’s Party, aren’t we?
Carlyle exhaled and stood back up.
We can’t just go around killing innocents.

[⋯⋯.]
...Ah. Sorry.
That was not the kind of thing to say in front of someone who had killed more innocents than anyone.

Especially when he was currently borrowing her help.
Can you do it, Miss Hero? We have to break the brainwashing.
When demons pull tricks like this, they always use the worst, most depraved methods.

Usually, there’s no way to fix someone once they’ve been brainwashed—except death.
This was no different.
...They planted a bomb inside its head.

Carlyle studied the structure and came to a conclusion.
Try to deactivate it? Boom. Break the brainwashing? Boom. The beast dies? Boom.
[...Familiar method. So twisted it’s practically art. No matter what you do, they want you screwed.]

Demonic logic.
Carlyle sighed and asked,
Can you handle it?

[...Hm. Somehow.]
Not even she was omnipotent, after all.
Carlyle gave a small laugh and nodded.

“Miss Vespa, please... just focus on keeping yourself safe with Panhyma.”
“⋯⋯Huh?”
She blinked, confused. He gave her a sheepish smile.

“To be honest... I’ve never done this before either. No idea what’ll happen.”
Three seconds.
That’s how long he could endure merging his mind with the Holy Sword, which had been transformed into raw mana within him.

What he could accomplish in that time—Carlyle had no clue.
The Dean hadn’t explained it clearly, and the Holy Sword hadn’t offered much guidance either.
So, he’d have to experience it firsthand.

...Miss Hero.
[What.]
Don’t do that thing again.

[What thing.]
That weird teenage thing. Don’t shout some cringy move name.
It was embarrassing enough already.

With that, he activated Tears of the Star—
—and merged his consciousness with the Holy Sword.
“⋯⋯!”

And instantly, something felt different from last time.
A bizarre sensation, like the inside and outside of his body had flipped. His perception blurred; his consciousness flickered.
The next moment—

Carlyle became the Holy Sword.
[......]
...What the hell.

He blinked.
And realized he could see himself—his own body—swinging the sword.
It hit him instantly.

...She’s in there.
That was Gray.
They had swapped.

Carlyle was the sword.
And Miss Hero was in Carlyle’s body.
Which meant—
Miss Hero had been manifested into the world for three full seconds.

“This form actually lasts a little longer than three seconds. More like... twenty?”
She said that, using his body, confirming everything.
Apparently, she’d known this would happen all along.

...Wait, hold on.
[Why is it longer now?!]
“I slowed down time.”

[?]
“In a space filled with my mana, I can manipulate localized time flow. It’s hard to maintain, though.”
[......???]

What the hell was this lunatic talking about?
She was casually saying things that broke the laws of physics.
Looking closer, there was indeed a grey dome of mana surrounding Carlyle’s body.

Everything inside it was moving slower.
[...Are you actually a god?]
The Dean had once said she could twist reality’s rules... but he didn’t think it was literally true.

“I’m not a god. But among humans, I’m probably the closest thing.”
Gray replied with a stretch—using Carlyle’s body.
“With twenty seconds... I can get a lot done. I’m going to take care of everything while I’ve got the chance.”

[What are you even talking about? We’ve got more important things—]
“Who do you think you’re talking to, dear?”
Even with just three seconds, a Hero could annihilate an entire region.

Twenty seconds?
“I can do anything.”
And with those words, she snapped her fingers.

The grey dome expanded outward.
[......]
Suddenly, Carlyle felt uneasy.

[Miss Hero, I told you not to—]
He tried to interrupt, worried she’d say something outrageous.
But she didn’t care.

Her voice dropped, solemn and low.
“Final Technique... Domain Expansion—”
[I told you not to say that crap—!!]

Even if their bickering was ridiculous, the manifestation’s effect was very real.
The grey dome erupting from Carlyle’s body—
—began to consume the entire area.

***
Very few people knew what it looked like when a Hero used their full strength.
But to devastate the surroundings just by running—that was something only a Hero could do.

Every step shattered the ground. Shockwaves rippled from her path, leveling everything in her way...
“⋯⋯.”
And yet, despite creating such a surreal scene, Gray looked deeply anxious.

Because inside that barrier, a variable beyond her control was unfolding.
...Those bastards better not die.
If they did—

She’d kill them.
...Even if they were already dead, she’d kill them again.
If Carlyle or Lionel were here, they’d probably laugh and say That’s so Gray of you, but that was all she could think.

So when she felt a tremor of immense power pulsing from within the barrier—
It was only natural for her to turn toward it on instinct.
“⋯⋯?”

But.
Confusion flickered in her gaze.
Even her legs, which hadn’t once stopped moving, came to a halt.

That’s not the Black Mirror Beast?
This wasn’t mana from a beast-class catastrophe.
It was something else entirely.

Even just looking at it, it was obvious—the exploding aura wasn’t black like the beast’s, but grey.
It had grown massive in an instant, visible even without superhuman vision.
“⋯⋯.”

And the energy...
It felt horribly familiar.
“...My own?”

That blast of mana—
Was unmistakably her own.
Even in a dazed state, Gray instinctively scanned for the source of the anomaly.

She searched with her eyes.
It didn’t take long to spot the orange-haired man.
“⋯⋯.”

Or rather—
The something using his body as a vessel.
That form—

That presence radiating her own mana—
She had seen it before.
Something that strangely resembled her.

No—more than resembled. It was nearly identical.
Only this time, it was even clearer.
It was wielding her power directly now, and its identity stood out sharply.

That face. That form.
It was familiar.
So familiar it felt like a branding iron scorched across her brain.

“⋯⋯.”
There was only one logical conclusion.
...But she knew it couldn’t be true.

That person was already dead.
And there was no reason she should appear here.
Yet, there was only one towering figure Gray knew of who looked so much like herself.

“...Mom?”
The word slipped out before she realized it.
***

[System Message]
▶ Target “Gray” has recognized her “self within the Holy Sword.”
▶ A related event will be generated in the future!