[FATE] OP Demon King Across Multiverse!

"Hey! Oi, kid, answer me! Saber's Master, what the hell is going on?!"

Cú Chulainn's voice pulled Ryuu back from his silent rage over his lost Demon King Points.

He turned to face the Lancer-turned-Caster, his expression a mix of exhaustion and irritation.

But—he knew they'd be fighting together for now.

Ryuu sighed. "To be honest? I don't fully understand either. But one thing's certain—the Holy Grail War isn't over."

---

Cú Chulainn frowned. "What do you mean? Saber already took the Holy Grail, didn't she?"

Ryuu's golden pupils gleamed, and he raised his right hand—showing the partially used Command Seal.

"If Saber had truly won through normal means, I wouldn't still be here."

Cú Chulainn's expression darkened.

He clicked his tongue. "Tch. So someone's pulling the strings from behind the scenes."

"Glad to see you're not completely stupid." Ryuu smirked. "You said Saber found you already?"

---

Cú Chulainn winced, his pride taking a hit.

"Yeah… and she wasn't alone."

"What?"

"Archer was with her."

Ryuu's eyes narrowed.

"Damn it. Saber's already forming alliances?"

Cú Chulainn crossed his arms. "If I hadn't been quick on my feet—uh, I mean, if I wasn't so skilled, I'd be dead already."

"You're telling me they already defeated Archer?" Ryuu muttered. "Tch. We don't have time."

He clenched his fists. "When the hell is Chaldea going to show up?"

"Oi. Chaldea? The hell is that?"

Cú Chulainn caught onto the name, his eyes sharp with suspicion.

Ryuu sighed.

"I don't know the full details. But what I do know is that they're the only ones who can stop this mess."

Cú Chulainn gritted his teeth.

"So what, we just sit around and wait for these guys?"

"No." Ryuu smirked. "Caster—how about a temporary contract?"

Cú Chulainn stiffened.

He looked away, scratching his head. "Tch. You saw through me, huh?"

"You're running on fumes, aren't you?" Ryuu folded his arms. "Without a Master's mana supply, you're barely surviving on these spiritual veins."

Cú Chulainn grumbled.

"Yeah, yeah, you got me. If I leave this place, I'll probably vanish."

Ryuu extended his right hand. "Then make the contract with me."

Cú Chulainn hesitated—but after a long pause, he sighed.

"Fine. I still don't like you, but I'm not an idiot. Let's do it, Master."

A flash of light connected them—Cú Chulainn was now officially Ryuu's second Servant.

---

Ryuu barely contained his grin.

"Who said I was saving the world?"

He wasn't doing this for some heroic cause.

No—this was about power.

With Cú Chulainn fighting beside him, his chances of farming more Demon King Points had just skyrocketed.

And as for Chaldea?

Ryuu had no plans to join them.

He'd cooperate if it benefited him, but if they got in his way—

They'd die just like everyone else.

---

"Alright, Master. What's our next move?"

"Simple." Ryuu cracked his knuckles. "We hunt the remaining Servants. The fewer enemies, the better."

Cú Chulainn's eyes gleamed with excitement.

"Now we're talking."

But then—

A crimson light cut through the sky, heading straight for them.

---

Ryuu and Cú Chulainn dodged instinctively, the projectile slamming into the ground and blowing apart the area.

A figure stood atop the rubble.

Dressed in a red coat, dual swords in hand—

Archer.

His piercing golden eyes locked onto Ryuu.

"Interesting. You're the one Saber warned me about."

Ryuu narrowed his gaze.

"And you're still alive, huh? Tch. Didn't Saber finish the job?"

Archer scoffed.

"She doesn't trust me completely. That's why I'm here to confirm something."

He raised his blades.

"How did you resist the Curse of Excalibur?"

---

Ryuu smirked.

"Wouldn't you like to know?"

Archer sighed.

"Fine. If you won't talk, I'll just kill you myself."

---

Cú Chulainn's grip tightened on his staff.

"Master, this guy's mine."

"Heh. Be my guest."

Cú Chulainn charged forward, swinging his staff like a spear.

Archer smirked—his hands glowing as he projected Kanshou and Bakuya.

The two warriors clashed, their weapons ringing out in rapid succession.

Archer's speed was superior, but Cú Chulainn had decades of battle instinct.

They were evenly matched.

---

Ryuu watched for a moment before his golden pupils flashed.

"No point letting this fight drag on."

Berserk Blood – Second Activation.

His body tensed, muscles amplifying as his draconic aura flared.

In a blur, he vanished from sight—

And reappeared behind Archer.

SLASH!

Archer barely dodged in time, but Ryuu's blade cut across his chest.

Blood splattered onto the pavement.

Archer stumbled back, his expression briefly shocked.

"…You're fast."

---

Ryuu grinned.

"What's wrong, Faker? Didn't see that coming?"

Archer grimaced.

"…Tch. I see. You really are a threat."

---

Cú Chulainn seized the moment.

"Caster Rune—Flame Javelin!"

A massive fireball formed at the tip of his staff—

And hurled toward Archer.

Archer gritted his teeth, realizing he couldn't dodge both attacks.

Ryuu lunged forward as Cú Chulainn's fireball exploded.

---

BOOOOOOOM!

The blast rocked the battlefield.

As the flames settled—

Archer was gone.

Only a burning crater remained.

---

Cú Chulainn exhaled.

"Damn. That guy was tough."

Ryuu stared at the wreckage, his golden eyes calculating.

---

Ryuu frowned.

"No confirmation of death. That bastard might still be alive."

Cú Chulainn grumbled.

"If he's still kicking, we'll deal with him later."

Ryuu sighed. "Yeah. Let's move."

---

As they disappeared into the burning city, one thing was clear—

The Holy Grail War wasn't over.

It was just getting started.

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