[FATE] OP Demon King Across Multiverse!

After receiving a full debriefing from Chaldea, Olga reluctantly handed over operational control to Dr. Roman.

Meanwhile, Ryuu remained silent, his gaze fixed on Mash.

The intensity of his stare made Mash visibly uneasy. She fidgeted slightly, unsure how to respond.

"U-Um… Mr. Ryuu, is something wrong?"

"No, not really." Ryuu smirked slightly. "I'm just curious… The idea of fusing a human with a Heroic Spirit to create a Demi-Servant—it's pretty damn fascinating."

"It wasn't exactly a perfect fusion," Mash explained. "At the last moment, the Heroic Spirit I was meant to summon gave up his form and granted me this power. But I don't even know his true name or Noble Phantasm."

"Then," Cú Chulainn interjected, turning to Ritsuka Fujimaru, "your Master should be able to see it, right?"

Ritsuka—caught off guard—quickly waved her hands, flustered.

"N-No! I barely understand anything about Heroic Spirits or Servants! I'm just figuring things out as I go!"

Ryuu narrowed his eyes. "So this whole place—Singularity F—exists because someone messed with history, right?"

"Exactly," Ritsuka nodded. "The Holy Grail War should have taken place here in Fuyuki City, 2004, but Chaldeas detected that all of human history had been wiped out. We still don't know the cause."

Cú Chulainn crossed his arms, frowning. "Yeah, that makes sense. If things had gone normally, I wouldn't have ended up summoned here like this."

Smirking, he casually pointed a thumb at Ryuu.

"If you need answers, this guy should be your best bet. He was Saber's original Master before she went rogue and wrecked this whole war."

The group turned to Ryuu, now the center of attention.

Ryuu scowled at Cú Chulainn. Damn hound, selling me out just like that.

He let out a short sigh and instead directed their attention upward.

"See that ring of light in the sky?"

The group followed his gaze. The eerie halo of energy loomed in the dark sky, its center a bottomless abyss of black.

The sheer pressure of magical energy emanating from it was enough to make even Mash instinctively tighten her grip on her shield.

"T-That's… unnatural," Mash whispered.

"That thing," Ryuu muttered, "is probably why this whole world is screwed."

Despite the eternal night and endless flames consuming the city, that circle of light never faded.

It was like an all-seeing eye—watching, waiting.

Ryuu narrowed his golden eyes. He was starting to really wonder who won the original version of this Holy Grail War.

"You're from the future," he finally said, turning back to Ritsuka and Olga. "So tell me—who was the winner of the Fuyuki Grail War?"

Olga shook her head. "No record exists. This battle's outcome was never documented."

Just like the Fifth Holy Grail War, huh… Ryuu thought.

Before he could press the issue further—

His Instinct suddenly screamed at him.

Danger!

Without thinking, Ryuu grabbed Ritsuka, hoisting her into his arms and leaping backward.

SHING!

In the spot where Ritsuka had been standing, several luminous white chains impaled the ground.

A slow, sultry voice echoed from the shadows.

"Hmm… To think you'd dodge that. How interesting. A fresh new prey to play with…"

A figure emerged from the darkness—a tall woman clad in a flowing black robe, her violet hair cascading down her back, and golden snake-like eyes piercing through the night.

In her hand, she wielded a massive scythe-like spear.

Ryuu instantly recognized her.

"Lancer… Medusa."

Cú Chulainn and Mash rushed to Ryuu's side, both raising their weapons in defensive stances.

Medusa tilted her head slightly, as if studying them with interest.

"My, my… What a wonderful night for a hunt," she purred. "A new Servant, a new Master… fresh offerings for my hunt."

Ryuu scoffed. "Hah. You weren't nearly this excited when we first crossed paths, Lancer."

Medusa smirked. "You weren't chosen by my Lord back then."

Cú Chulainn gritted his teeth. "Oh? So now you're just a lapdog following orders, huh?"

Medusa's smirk widened. "Lapdog? No, no. I'm simply a predator."

She suddenly vanished.

Fast! Ryuu's mind screamed.

In an instant, Medusa was behind him, her spear slashing downward.

Ryuu barely had time to parry with his blade, the sheer force sending him skidding backward.

Mash raised her shield to protect Ritsuka. "Leave this to me, Mr. Ryuu! Please take Master and retreat!"

Ryuu grinned, rolling his shoulders.

"Hah. You're a good kid, but let me make something clear—I don't run."

"But—!"

"He's got this," Cú Chulainn interrupted. "Trust me, kid, my Master isn't your average human."

Mash hesitated but ultimately nodded.

Ryuu turned his full focus to Medusa.

His golden pupils burned brightly—not from instinct, but from something deeper.

His Geass.

Let's see which is stronger—your Mystic Eyes of Petrification or my Absolute Command.

---

"Leave it to you? Hah. What an amusing joke."

Medusa lunged again, her chains slithering toward Ryuu.

Ryuu smirked. I've got you now.

"Geass—Absolute Order!"

His left eye flared crimson, the Geass sigil glowing brightly.

Medusa froze.

For a split second, her entire body locked up, her Mystic Eyes losing their glow.

That was all the opening Ryuu needed.

Second Stage—Dragon's Blood Awakening.

Golden scales formed across his arms, his speed doubled, and his power skyrocketed.

He vanished.

A boom echoed as he reappeared right in front of Medusa, his blade swinging upward in a brutal arc.

SHINK!

Medusa barely managed to jump away, but a deep gash now ran along her thigh.

She landed, clutching her wound, eyes narrowed.

"You…!"

She was about to activate her Mystic Eyes of Petrification—

But Cú Chulainn's fireball runes exploded around her, forcing her to leap away once more.

"I'd love to keep playing," Cú Chulainn chuckled, spinning his blade. "But I've got a Master to protect."

Medusa gritted her teeth!

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