Shirou, who returned from the Fairy Kingdom

Even if he was the reincarnation of his half-brother, a mere monster was not enough to kill this hero.

What truly killed him was the "Oath (Geis)".

It's worth noting that even Cú Chulainn, the great hero of Celtic mythology and the Son of Light, only made three "oaths" throughout his entire life.

The tragic hero, Diarmuid, carried more than double-digit Geis throughout his life.

Princess Grani, daughter of King Commark, once used a "vow" to force Diarmuid to elope with her at their wedding.

This sparked a conflict between Diarmuid and his lord Finn, leading to Diarmuid's sixteen-year exile.

There are many other vows besides these, such as:

"You may not refuse an invitation from a companion."

"You must participate in the hunt when you hear the hunting dogs barking."

"Hunting wild boars is prohibited"

"Will die from wild boar"

That's right—

Diarmuid's lord cleverly used these four "oaths" to plot his murder.

An oath is an absolute and inviolable destiny, and even the greatest heroes are no exception.

However, due to its absolute binding force and destiny power, the "Oath" can also bring unparalleled power to warriors.

The more "oaths" you make, the stronger the "power" you gain.

The more contradictory the rules of the "oath," the more terrifying the "power" gained.

Diarmuid, whose entire life was bound by the "oath," completely abandoned his knightly beliefs—

Symbolized by wearing the skin of a demonic boar, they transformed the power of these "oaths" into terrifying demonic forces.

"how come……"

Saber was stunned.

Meanwhile, Diarmuid's wound from Shirou's Reversal Sword has fully healed.

But it didn't seem like healing magic at all; it was more like the regeneration of monsters, just like the tentacle monsters she had just killed.

"Lancer, who exactly are you...?"

"The class remains Lancer, but the spirit origin has been twisted beyond recognition."

Shirou stared expressionlessly at the handsome man who had undergone the transformation, repeating Lady Avalon's whisper in his ear.

"Now, he could easily be called the Avenger."

"the Avengers……!?"

The one who made the startled, trembling voice was Irisviel.

It's normal for her to react that way.

After all, sixty years ago, during the "third time," Einzbern had already summoned a Heroic Spirit of the Avenger class.

According to records, he was an incredibly weak fellow, and it was because of him that the homunculus race was defeated early on, which could even be said to be Ahadon's greatest humiliation.

However, the Lancer before her completely overturned Irisviel's perception that "the Avengers are weak".

How is that possible... In terms of ability and magical power alone, he is already on par with Saber!

If Artoria is a red dragon with the appearance of a young girl, then Diarmuid, now draped in the skin of a demon boar, is a cursed divine beast unable to maintain his human form.

"Ha, I got found out... I should have known better than to pretend. I felt nauseous just pretending to be 'Diarmuid' for another second."

Lancer was enveloped in a dark mist, and his once handsome face became twisted and ferocious.

“That’s right, just as you said, my spirit origin has changed.”

But make no mistake, this isn't some kind of distortion, it's evolution—

Is the world so wonderful after abandoning chivalry? Is breathing really such a pleasant thing?

Diarmuid, now in his semi-monster form, can do the same thing as Saber: gain a large amount of magical energy with just a single breath.

"Lancer! Wake up!"

"I feel wonderful right now, more fulfilled than ever before! You're the one who needs to wake up, Saber!"

Lancer's voice was like an echo from the depths of hell.

"Whether it's you, or that shameful, lustful son of God (Finn McCool)..."

How could you, who have possessed power from the very beginning, possibly understand the mindset of mortals!

He dedicated his life to martial arts, but in the end, he still couldn't compare to the bloodline you were born with.

Now I finally understand that chivalry is utterly worthless; only power is the sole truth in this world.

That kid just said I'm an Avenger? Ah, maybe so...

If you were to ask me who I am seeking revenge against.

Saber, it's not you, it's the hypocrisy called "chivalry."

"..."

Saber's expression was distorted.

"Hmph... How laughable, King of Knights."

Lancer said with a sinister grin, "Are you that upset to see someone weaker than you gain power?"

"I never thought of it that way—"

"Your expression betrays you; you're looking at me with jealousy."

Diarmuid the Demon sneered, "No matter how well you disguise yourself, it won't change... brat, let him finish what he has to say."

Black light and magical energy flowed through the forest in the dead of night.

Just as Lancer was speaking, Shirou silently slashed at him.

However, Diarmuid simply raised his right arm to block it.

"I've been thinking about this for a while now."

Lancer said with a frown as he swung the Crimson Demon Sword to send Shirou flying.

"You little brat, you wouldn't happen to be one of my kind, would you?"

Diarmuid stared intently at the only eyes visible through Shirou's bone mask.

"I can't be wrong, those are the eyes of someone who will stop at nothing to win."

In the end, if you weren't one of my kind, how did you figure out that I was planning to kill that woman?

You've thought the same thing I have, haven't you? Get close to this woman and kill her.

"Shirou would never do such a thing!"

Irisviel spoke out in defense of the boy, but was so frightened by a glare from Lancer that her legs trembled.

"Now you've changed your mind for other purposes, anyway... it's all about using her and her Saber, isn't it?"

Haha, after all, they're both naive women who are easy to please.

"Enough with the jokes, Lancer!"

Artoria pointed the invisible sword at the demon.

"It's a real shame that our agreement to fight together has come to an end."

Diarmuid Ua Duibhne, I will defeat you—no, exterminate you—with all my might.

Saber's attitude was completely different from that during the Warehouse Street battle.

She no longer regarded Lancer as a respectable heroic spirit, but as an evil spirit that must be destroyed.

In her view, the threat posed by Diarmuid the Demon was no less than that of the Sea Demon, and perhaps even greater.

To use an imperfect analogy, the sea monster might devour a city, but if this man were to obtain the Holy Grail... the consequences would be unimaginable.

Lancer also adopted a fighting stance.

He wielded a red magic spear in his left hand and a red magic sword in his right—the strongest equipment combination in Diarmuid's legend—along with the skin of the magic boar bearing a dozen "oaths."

He is now no less than any hero in mythology.

"Shirou, can I ask you for a favor?"

—Saber didn't say those words aloud, but instead cast a glance at the red-haired boy.

Having already developed a deep connection with her after the previous battle, Shirou nodded: "Leave the Sea Demon to me."

Saber possesses a Noble Phantasm that can defeat the Sea Demon in one hit.

However, it is clear that Lancer in front of her will not give her the chance to unleash her Noble Phantasm.

Diarmuid the Demon King's initial goal was to use Saber and her Master to defeat Caster.

Then, during this process, look for opportunities to monopolize the rewards from the raid, or even eliminate the Saber group—

But now, the situation has changed.

Caster had already been killed before he arrived.

So now there's only one thing left to do.

Rather than defeating monsters, you should kill Irisviel first, as she might receive a Command Seal as a reward.

The Master in the distance, Kenneth, also accepted Lancer's point of view.

Although letting the sea monster enter the city troubled his conscience, he, as a magician, only had a sliver of conscience to begin with.

Saber and her Master are exhausted right now, so killing them is the best course of action.

Saber sensed Lancer's murderous intent towards her and turned to look at Shirou.

"I'm counting on you to delay the sea demon's entry into the town."

"I'll join you after I defeat Lancer, and we'll use our Noble Phantasms to take down that monster."

"what!"

Lancer let out a mocking laugh.

The naive Knight King told two absurd jokes in a row.

Saber will defeat Lancer.

The little devil can hold off the sea monster.

Neither of them is likely to happen.

"……I see."

Shirou looked toward the town of Fukayama, where the giant shadow of the sea monster in the thick fog looked like a moving mountain range.

"By the way, Saber, can I confirm something?"

"what?"

Shirou spoke with his back to the blonde girl and her Master.

"Even though I'm just supposed to hold that guy off... it wouldn't hurt to take him down, right?"

Volume 1, Chapter 59: "The Nameless King Returns"

"Even though I'm just supposed to hold this guy off... it wouldn't hurt to take him down, right?"

After Shirou said that, Artoria looked stunned.

Defeat it?

Defeat that otherworldly monster that has swelled to over a hundred meters above the ground and is equivalent to a demonic incarnation?

Saber doesn't think Shirou is capable of doing that.