Among those present, only Arcueid could somewhat match Astraea's strength. However, Arcueid had her own unresolved issues. While facing opponents with weaker combat abilities posed no significant challenge, contending with a widely renowned goddess like Astraea carried the risk of being ambushed by the hidden Crimson Moon within her.

The crucial point lay in the fact that the individuals from Illya's parallel world possessed the ability to achieve the impossible through the Class Cards. As someone hailed as the Eternal King, how could Shirou not live up to such a title? How could he not harness the power that rightfully belonged to him?

Astraea sensed Shirou's actions and launched an attack, but midway through, Arcueid intercepted her.

Since both Astraea and Arcueid had a preference for physical combat, Astraea swiftly discarded her scales and sword, opting to engage in a wrestling match with Arcueid.

Their clash was intense, whether it was Astraea throwing Arcueid over her back or Arcueid tearing through Astarte's body with her sharp claws.

Meanwhile, Shirou focused his concentration, gradually infusing the blank card with his magical energy. The magic crystal attached to the card started to activate, emitting a faint crackling sound.

"Crackle crackle crackle—"

His hand sank into the blank card, aiming towards the records of the Throne of Heroes.

"This Ainsworth family sure knows how to make a simple yet powerful tool."

The blank card itself was a magical crystal meticulously crafted by the ancient magecraft of the Ainsworth family, designed specifically to replicate the records housed within the Throne of Heroes. This ingenious creation enabled the Heroic Spirits to be duplicated in the form of Class Cards, granting their abilities to the Card's User.

What Shirou was about to do could easily be labeled as theft—a brazen act of thievery, plunder, and bootlegging! The Heroic Spirits residing within the Throne, sensing his actions, expressed their clear displeasure.

Yet, a select few Heroic Spirits, detecting a strangely familiar presence, responded eagerly, longing for their records to be duplicated by him.

However, he paid no heed to their appeals. He focused his attention solely on the unique record of the Throne of Heroes—a record that existed but lacked any form.

It was to this unique record that he aimed his gaze and reached for it.

It felt almost destined. That seat was meant for him and him alone—Fujimaru Shirou.

And its name was none other than—

The Eternal King!

Summoning the Eternal King was an impossible feat for anyone else; no one could hope to replicate his immense power. After all, the record that held his existence lacked any physical form.

The exclusive authority to wield the power of the Eternal King belonged solely to him, and no other.

For he was the Eternal King!

A burst of crackling energy filled the air, emanating from the blank card. Its radiant glow captured the attention of everyone present, even Astraea couldn't resist stealing a glance at it.

Within that card, Astraea could sense a power that surpassed mere mortal comprehension. It was a power so formidable that it sent shivers down the spines of even gods themselves.

Astraea, filled with a mixture of curiosity and apprehension, struggled against Arcueid's grip but found herself restrained. Impatience painted her expression.

The room fell into an eerie silence as all eyes fixated on the card clutched in Shirou's hand.

In that moment, the once blank card began its astonishing transformation. Colors seeped into its surface, and an undeniable surge of power coursed through its very core.

A collective question echoed through everyone's minds: What in the world was happening?

Shirou stared intently at the card in his hand. In that moment, the card transformed before his eyes, shedding its blankness and revealing the symbol of a magus and a series of letters spelling out "Caster."

With a firm grip, he held onto the Caster card and directed his gaze towards Astraea, who instinctively took a step back. There was something about the card that emitted a suppressed yet foreboding aura, leaving her with a sense of unease.

It felt like facing a natural enemy, an instinctual reaction that stirred within her.

"So, you wish to pass judgment on the sins of this King? But now, it appears that it is this King who shall pass judgment upon you!" He declared, channeling his magical energy into the card and unleashing the formidable power contained within the Caster card.

In a split second, the power and essence contained within the injected record enveloped his entire being.

"Install: Phantasm Summon · Eternal King!"

With a steely resolve etched on his face, Shirou was consumed by an unfathomable light. Once the light subsided, the Eternal King materialized before them.

Yet, as the onlookers laid their eyes upon the King who held dominion over everything, they couldn't help but be stunned.

The shock wasn't limited to the onlookers; even Astraea and Arcueid couldn't contain their astonishment.

"Shi... Shirou?" Arcueid stammered, her voice filled with disbelief.

"Yeah, it's me!" He replied, but as soon as the words escaped his lips, he couldn't help but pause. This voice wasn't his usual magnetic and firm tone; instead, it was somewhat soft and gentle, resembling that of a child.

Upon careful observation of his surroundings, he noticed that the people around him seemed to have grown much taller.

No. It wasn't that they had grown taller, but rather that he had become smaller!

Looking at his palm, he was surprised to find a pair of tender, childlike hands instead of his usual weathered ones.

As he looked into the mirror, expecting to see the image of a young king with an air of steel-like determination, he was taken aback. Instead, he saw a gentle and soft boy adorned with a crown and silver armor.

A six-year-old boy!

The boy's facial features were gentle, and his eyes sparkled like flames, emanating a kind expression.

And within him, a warm and tender feeling surged, washing over him.

It felt as if he had been transported back nine years, to a time before he had crossed paths with Camelot.

Confusion flooded his mind as he tried to comprehend the situation. What was happening to him? Just as the question lingered, a notification abruptly materialized before his eyes:

[Insufficient magical energy, unable to manifest adult form.]

The appearance of this message confirmed without a doubt that it was the ability of his second Noble Phantasm.

"Insufficient magical energy, huh... Well, that's a hassle," Young Shirou remarked, scratching the back of his head with a casual smile.

"And now I finally understand what it means to be a Servant... Transforming into a child, free from the weight of responsibility and with a mind that can't conceal anything... It's like having a split personality!"

A bright yet somewhat helpless smile adorned boy's face.

In that moment, he had gained a true taste of what it meant to be a Servant. Strictly speaking, he wasn't the same innocent boy anymore.

As an adult, Shirou possessed a mature way of thinking, carefully considering matters with the perspective of a king and striving for efficiency.

Initially, he believed that by using this "Install" ability, he would regain his own power. However, the reality wasn't that easy.

As a Servant, limited by the lack of sufficient magical energy, he was unable to manifest as the Eternal King in his adult form. Instead, he materialized as a child.

The crucial aspect to note was that despite his physical transformation, his personality and essence remained unchanged. However, the overwhelming surge of emotions, those uncontainable feelings—undoubtedly, they were the same emotions he had as a kid at the tender age of six!

Despite being the same person with the same memories and experiences, the manifestation of a Servant resulted in different emotions, mentality, and thought processes depending on the period the Servant was summoned.

While others might find themselves shocked by such a situation, Young Shirou simply showed a smile.

It was to be expected. The person standing before them was undoubtedly the genuine Shirou. However, as a result of the Class Card's influence, his emotions had regressed to that of a six-year-old.

Nevertheless, his experiences and memories remained intact, untouched by the transformation.

As he contemplated his current state, he couldn't help but be amazed at the stark contrast in his mentality and emotions as a Servant. It almost felt like having a split personality.

It now made sense why the Type-Moon franchise often depicted scenes of one's self battling, even killing one's self.

"Well, looks like I'm just a little kid at the end of the day!" He remarked with a tinge of amusement.

Astraea couldn't help but release a sigh of relief. Despite sensing an aura of her natural enemy from that Caster Card, the manifestation turned out to be nothing more than a child!

Young Shirou smiled mischievously and teased, "Don't underestimate me, Astraea. That would be a grave mistake. Is anger clouding your heart? Allow this King of Men to lend you an ear."

His smile was accompanied by a captivating gleam in his eyes, as if an exquisite flame burned within them.

Rather than scorching, it felt like the warmth of a cozy fireplace on a winter day, comforting to the very core of one's soul.

Even Astraea found herself stunned by the sight before her.