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

Chapter 76.1 The awakening of the gemstone

After Rust and Onyx had left.

Dia and Black Snake, left behind in the large room, were engaged in their respective battles.

Black Snake, under Onyx’s orders, fought to defeat Dia.

Dia, of her own volition, fought to protect the adventurers.

“【Corrosive Venom Melt】!”

From the small pot held by Black Snake, a stream of poison magic was unleashed.

Dia intercepted it with her 【Immortal Great Shield】.

Since there were injured adventurers lying behind her, avoiding the attack was never an option for her.

As a result, she was clearly on the defensive.

Even so, Dia did not retreat.

(I will definitely protect everyone here…!)

As she stopped the incoming poison magic without a moment’s rest, Dia reminded herself.

She had made a promise to Rust.

She vowed to protect everyone here.

When Citrine was taken away right before her eyes and she could do nothing, she felt utterly powerless.

This was her chance to redeem herself.

Thus, Dia was determined to face the Demon with just her shield, resolute to make up for her previous failure.

(I absolutely cannot lose!)

With that resolve, Dia considered her strategy.

It seemed that the Demon’s artifact was a typical catalyst-type artifact.

The benefits provided by the artifact itself were probably weak, and the main offensive power was likely the “magic” that could be cast from a distance.

The fact that the Demon continued to attack from afar without closing the distance was evidence of this.

(If I can just close the distance, I might be able to subdue her.)

With this thought, Dia charged towards Black Snake while holding her large shield.

Despite the continued poison magic attacks, she pressed on.

“Ha!”

When she reached close to Black Snake, she swung her shield sideways in an attempt to strike.

Thanks to the slight benefit of enhanced strength, her attacks were somewhat effective.

However, against a seasoned Demon, such moves were not easily effective.

Black Snake dodged the attack and flew away, once again creating distance between them.

Dia gritted her teeth silently and continued her assault with the shield, undeterred.

“Ugh, you’re so persistent!”

Even when trying to repel with poison magic, Dia had her shield.

Thus, she could charge in without hesitation, and Black Snake was frustrated by her persistence.

Eventually, the large shield, swung like an axe, pierced Black Snake’s side.

“Ugh—!”

It would have been great if this caused the artifact to explode or if she dropped it, but such luck did not happen.

Black Snake merely grimaced slightly.

The lack of divine power was frustrating.

As Dia bit her tongue silently, Black Snake looked down at her injured side with a puzzled frown.

She then suddenly relaxed her cheek and muttered meaningfully to herself.

“Heh, I see.”

“…?”

What could that muttering mean?

Before Dia could investigate the true meaning, Black Snake tilted her head and shifted her gaze toward her.

“Why is it that the poison doesn’t affect you? Normally, anyone else would be unable to move a single finger by now due to the poison.”

Asked this, Dia glanced down at her own body.

Even though she blocked the poison magic with her shield, she couldn’t completely block it.

The poison liquid that struck her exploded into fine droplets that stuck to her body.

Even that should have been enough to spread the poison.

If not, the dissolving properties of the poison could have turned her body into a mess by now.

It was inexplicable to Black Snake why Dia stood there unharmed.

In response to this question, Dia replied curtly.

“Well, I wonder why that is.”

“…”

Black Snake’s brows twitched slightly.

It seemed to bother her, but she wasn’t expecting a straightforward explanation.

“Well, it’s probably due to the abilities of your artifact. Anyway, since I’ve figured out that the poison doesn’t work on you, that’s fine.”

Black Snake spoke with a tone that suggested she was somewhat sulking.

It seemed that Diana’s artifact—【Immortal Great Shield】—had a skill called ‘Immortality.’

This skill granted resistance to poison and curses, rendering them completely ineffective.

Additionally, the artifact’s durability did not decrease.

That’s why Dia remained unaffected by Black Snake’s poison magic.

(But, it does hurt a bit.)

Even though the poison is completely nullified, the corrosive properties are not.

The poison droplets that stuck to her exposed skin were still burning her, regardless of her resistance.

It was indeed somewhat painful.

However, thanks to the artifact’s benefits, the damage wasn’t significant.

So she could keep attacking without fear. That was clear once again.

While thinking that, Black Snake had regained a smirk on her snake-like face.

Then, unexpectedly, she shifted her gaze to the side.

What could she be looking at? Dia wondered, but before she could figure it out, Black Snake sighed and muttered.

“Ha, I suppose I have no choice but to target those people, after all?”

“——!?”

Ahead of Black Snake’s gaze were the injured adventurers.

Realizing this too late, Dia rushed back to protect them.

“【Corrosive Venom Melt】!”

Mocking Dia’s efforts, Black Snake mercilessly unleashed poison magic.

Her target was not Dia, but the fallen adventurers.

“Ugh——!”

At the last moment, Dia slipped between the adventurers and the poison magic.

She raised her shield to intercept the magic and prevent the damage.

If she had been even a moment slower… That thought made her break into a cold sweat, and she narrowed her eyes to glare at Black Snake.

“Oh, you managed to make it in time.”

“……”

Dia bit her lip behind the shield.

With the adventurers being targeted, she had no choice but to focus solely on defense.

It was effectively the same as having hostages.

She couldn’t attack the enemy.

Attacking would create openings, allowing Black Snake to target the adventurers as she did now.

What should she do…

(…I suppose I can only endure.)

If there’s any remaining method to resolve this, it’s probably that one.

In simple terms, she must endure the poison magic until Black Snake’s mana runs out.

If she can do that, Black Snake will be unable to use his magic and will be rendered completely powerless.

Above all, she had already learned from the previous attack that hitting with a shield lacking divine power was pointless.

Given the current disadvantageous situation, this is the only approach left for her.

So endure. Even if it hurts, don’t run away. Be the impenetrable wall.

She can do it.

“How about this?”

As if reading Dia’s resolve, Black Snake smiled.

Then, unexpectedly, she took out a long, narrow vial from her pocket.

Inside it, a dark red liquid swirled.

(Is that… blood?)

The exact source of the blood was unclear.

But the unique, thick viscosity of the liquid clearly indicated it was blood from a living being.

Black Snake shook the vial, then flicked off the wax-sealed cork with her fingers.

For some reason, she then began pouring the blood into the artifact’s jar.

What is she trying to do…? Dia wondered as Black Snake finished pouring all the blood from the vial and readied the jar again.

“【Corrosive Venom Melt】!”

In an instant, a new type of poison projectile was shot from the jar.

This was completely different from what had come before.

It was much larger, darker in color, and clearly more powerful.

The force of the shot was also noticeably stronger.

Dia braced her hand holding the shield, but she was hit by a shock unlike anything she had felt before.

“Ugh——!”

Heavy. It felt like a full-speed carriage had slammed into her.

She was almost blown off her feet.

Additionally, the poison’s potency seemed to have increased dramatically.

The tiny poison droplets on her body burned her skin more intensely and painfully.

“Ugh… ugh…!”

Wincing in pain, Dia desperately tried to understand why Black Snake’s poison magic had suddenly become so powerful.

It was likely because…

(This artifact’s hidden ability skill. The “blood” must be the activation condition…)

Dia’s guess was correct. Black Snake’s【Great Serpent Orochi’s Poison Jar】had a skill called “Blood Offering.”

By pouring the blood of living creatures into the jar, the power of the magic could be enhanced.

The blood of particularly strong beings would enhance the magic even more.

Therefore, Black Snake carried vials of human and demon blood with her.

If he poured that blood into his magic, it would be disastrous—Dia’s intuition was right, and perhaps it showed on her face, for Black Snake grinned and said:

“You’ve figured it out, I see. Now, try to block all of it with that shield as I keep coming!”

Saying this, she took out another vial of blood and started pouring it into the jar.

As soon as she finished, she immediately cast the poison magic again.

Another powerful poison spell exploded against the great shield.

“Ugh——!”

Poison droplets danced and the liquid that clung to her skin corroded it.

She said the poison wouldn’t affect her. However, her body was gradually being damaged by the corrosive properties.

If she didn’t stop the enhancement of magic through that blood, defeat was inevitable.

But considering the distance from Black Snake, it was incredibly difficult to approach her between her poison attacks.

The optimal distance allowed her to pour blood into the jar and attack with a comfortable margin.

She must be maintaining this distance intentionally.

At this rate, she would continue to be hit by powerful poison spells and eventually die.

“【Corrosive Venom Melt】!”

Yet, escaping was not an option for Dia.

If she retreated, the adventurers behind her would become victims.

Unlike her, they had no poison resistance and no artifact to protect them.

If they were hit by this poison magic, there would be no chance of survival.

So she must endure. No matter how painful or difficult it is. She must be the shield for everyone.

“Ugh… ugh…!”

Despite the relentless poison attacks, Dia gritted her teeth and persevered.

Even as pain seared through her body, she continued to hold the shield.

Seeing her tattered state, Black Snake maintained a faint, mocking smile as she continued her poison attacks.

“I haven’t forgotten what you said earlier. You promised not to let the adventurers here get hurt, didn’t you? It must be tough having so many people to protect.”

It was meant to be ironic. Her disdainful gaze made that clear.

“And I’ve learned something from our fight. You don’t have the power to defeat demons, do you?”

“……”

“I didn’t feel any pain when hit by that huge shield. I’d guess it barely has any divine power. That’s why you can’t defeat demons. You can only protect yourself. How pitiable for an adventurer.”

While defending against the poison magic, Dia clenched her teeth behind the shield.

It was inevitable that the lack of divine power would eventually be discovered.

That was unavoidable.

What she disliked most was having her “weakness” exposed to her.

As expected, Black Snake, with a serpent-like persistence, pressed on with her harsh words.

“Is that why you’re acting alongside him? You’re letting him deal with the demons while you stay clean and watch from above. What a comfortable position you have.”

She understood that better than anyone else.

She knew she was burdening Rust more than she should.

She knew she was clearly doing less compared to Rust.

She knew all of that too well.

Confronted with the reality she had been avoiding, she stiffened up, and Black Snake delivered the cutting remark that hit the core of the matter.

“Are you just pretending to protect with that shield, while it’s actually you who are being protected?”

“……”

Those words struck Dia more deeply than she had anticipated.

The idea that she was merely pretending to protect, while it was she who was actually being protected, was a painful realization. The pain in her heart was a confirmation that this was indeed the truth.

She began to lose sight of her own purpose.