When I Tried Strengthening 【Rusted Sword】, It Evolved Into An Overpowered Magic Sword

Chapter 77.3 My reason for fighting

With a sharp gaze, I pointed the “Cursed Magic Sword” at Onyx.

He stood there, stunned, his face frozen in surprise. Gradually, he frowned and glared at me.

“I don’t get it. Why are you so determined to save her? Why protect her? Even if you save her, there’s no place for her. The human world will never accept her. It’s pointless, no matter how you look at it.”

To a demon driven by selfish desires, my actions were incomprehensible.

He must have been wondering ever since I appeared here.

I might not be able to save Citrine. Even if I do, there’s no guarantee of a happy future.

Helio said something similar. That demons are enemies. That it’s an adventurer’s duty to defeat them.

So why do I try to save her? Why am I fighting?

“Rust, I know you can do it.”

It’s simple.

There’s no need to think about it.

There’s only one reason why I fight.

“Behind me, there’s a crying girl. In front of me, there’s the one who made her cry.”

With Citrine behind me, I shouted at Onyx.

“A reason to fight—just that is enough!”

Humans or demons—it doesn’t matter.

Reason and common sense be damned.

I fight because there’s a crying girl.

I want to stop her tears and look cool doing it.

I admired that person who always acted cool, like an older sister.

When I think about it, the first hero I ever looked up to might have been that bold, loud, and cool childhood friend.

So, I’ll become strong like her.

I won’t fail anymore. I won’t falter. I won’t lose.

I’m going to win this fight.

I gripped the hilt of the “Cursed Magic Sword” and kicked off the ground with all my might.

“Enchant Magic—[Dark Thunder Cry]!”

As I shouted, black lightning crackled along the blade.

Leaving behind the roar of thunder, I charged at Onyx, who was readying himself for my attack.

Using magic drained my stamina.

The curses of the magic sword and the demon blade caused my whole body to ache.

If I let my guard down, I might lose consciousness any moment.

But I kept running.

“Looks like you’re desperate to die, Rust Stone! Then give it your all and let me kill you! I’ll be the one to take your life!”

Onyx sheathed his blade at his right hip, assuming that stance again.

Before my sword could reach him, he vanished, leaving behind a shockwave and a deafening noise.

No, this time I didn’t miss it.

I barely managed to see him closing in at an incredible speed, his wave-patterned haori/kimono jacket fluttering, as he drew his blade.

The blade, drawn from his right hip, left a black streak as it slashed horizontally.

I caught it with my eyes, and met it with my magic sword in my right hand.

I lowered my right arm, bringing the magic sword up to deflect the blade from below.

A heavy impact traveled through my right hand, accompanied by a burst of sparks and lightning.

“Grh—!”

Onyx gritted his teeth.

I saw his blade get knocked back forcefully, causing his upper body to recoil.

His front was open for just a moment.

This is my chance!

I swiftly drew back the magic sword to my left hip and aimed a powerful strike at Onyx’s right side.

“Haaah!”

The blade bit into his hard armor.

But it only pierced a little before stopping, unable to cut any deeper.

It was tough. I couldn’t slice through.

Still, I pushed the blade with all my might.

Gripping the “Cursed Magic Sword” with all the strength I had in my right hand.

“Haha! You can’t cut me with that!!!”

“Ugh… Uuu…!”

While pushing the blade in, I saw Onyx’s eerie smile as he raised his blade.

I refused to back down. I wouldn’t step back even an inch from this spot.

I had to take him down with this one strike!

In that moment, my left hand, which had been idle, moved quickly and sharply.

It grasped the hilt of the magic sword I held in my right hand, gripping it tightly with both hands.

Then, I imagined it.

Black lightning with my right hand. Black flames with my left.

Believe in yourself.

I can do this…

“…Enchant Magic”

I can definitely do it!

“【Black Flame Hellflare】!!!”

As I shouted, new, pitch-black flames erupted from the sword, which had been wrapped in black lightning.

The flames intertwined with the lightning, covering the blade and illuminating both me and Onyx with a blinding light.

The ultimate technique of simultaneously activating two enchant magic effects on a artifact.

It’s called Dual Enchant Magic.

Despite numerous failures, I finally managed to complete it here and now.

In that instant, the blade, previously hindered by the hard magic armor, began to sink in as if it had remembered its purpose.

The sacred power of the weapon was amplified, temporarily surpassing the hardness of the magic armor.

This should work.

—Cut through!

“Ha… Aaaaahhhhh—!!!”

I let out a roar from the depths of my throat and swung the magic sword with all my strength.

The magic sword slashed through Onyx’s body, leaving a trail of fire and lightning.

And, as intense sparks flew—

The blade that entered Onyx’s right side burst forth, scattering fresh blood as it exited his left side.

“Gu… Aah…!”

The stunned Onyx, now split in half, fell lifelessly to the ground.

Meanwhile, I remained unable to move from the spot for a while, still holding the 【Cursed Magic Sword】.

Eventually, I gasped for breath, my eyes fixed on the sword in my hands.

The blade still held black flames and black lightning, writhing and intertwining.

“Dual… Enchant Magic…”

I did it.

I succeeded in this critical moment.

I thought this was the only way to cut through Onyx’s magic armor.

Even though the two enchantments had clashed and failed repeatedly, now they combined perfectly.

I’m glad I tried it with confidence.

“What… was that…! That technique…!”

Onyx, now only half of himself, looked up at me with a furious glare.

In response, I decided it wasn’t necessary to explain, so I remained silent.

As I looked down at him in silence, he shouted even more furiously, his face contorted with anger.

“Damn it… who the hell…! You had such a technique hidden…!”

It seemed he couldn’t believe he had lost and was enraged by the fact that I hadn’t used my full strength until the very end.

I hadn’t hidden any techniques. I had been giving it my all from the start.

I had just managed to become a little stronger right here and now.

Onyx continued to mutter fragmented words, his expression one of dissatisfaction.

“Damn… it…”

With those final words, he turned into particles of light and vanished from our sight.

All that remained was a single katana, which had caused me so much suffering and likely absorbed the blood of many people.

As I looked at the vanquished Onyx, I finally felt the sense of “victory.”

Meeting the gaze of the dazed Citrine, that feeling of victory grew even stronger.

A sigh of relief escaped me.

Both of us were alive.

I was able to save Citrine without showing her the horrific reality.

“Citrine, are you okay—”

At the moment I tried to speak—

Suddenly, my vision blurred.

“What… is happening…?”

It was as if the world itself had flipped, and I found myself on the cold ground without realizing how I got there.

I could no longer muster any strength, and even speaking became difficult.

Gradually, I became aware of the pain and exhaustion throughout my body, and I tried to comprehend the situation with a foggy mind.

This must be the effect of the curse.

It wasn’t simply because I had relaxed after the tension.

The curse on Onyx’s katana should be lifted by now.

So, the cause must be the curse hidden within the 【Cursed Magic Sword】.

Even at a time like this, it seemed to mercilessly torment me.

Come to think of it, how long have I been using it?

This was the first time I had used the 【Cursed Magic Sword】 for such a prolonged period.

That’s why I ended up collapsing. I had definitely used it for too long.

It was probably a miracle that I could fight as much as I did.

Moreover, activating the Dual Enchantment with two types of magic must have greatly drained my stamina, serving as the final blow.

When I looked down, the 【Cursed Magic Sword】 had reverted to the 【Rusted Sword】.

Even though I still needed to fight, I couldn’t evolve it into a magic sword.

I still needed to go rescue Dia and the other adventurers.

Those thoughts remained unfulfilled, and with Citrine’s frantic figure rushing towards me being the last thing I saw, my consciousness faded once again.