High School DxD: “The future Harem King”

An Unexpected Attack – Testing Su Hai's Strength

Su Hai stood still, his gaze flicking between Rias and Akeno, who had led him to this secluded area.

His instincts told him that this wasn't just a simple conversation.

"So, Rias-san… what exactly did you bring me here for?"

However, neither Rias nor Akeno answered.

Instead—

A figure suddenly lunged toward Su Hai, sword in hand, moving at an incredible speed!

Su Hai's senses flared, detecting the danger instantly.

His body moved on instinct, quickly stepping back to avoid the attack.

At the same time, he reached into his System Space, summoning the Sun Blade in an instant.

His stance shifted automatically, his grip firm as his body flowed into a combat-ready position—

Breath of Thunder.

His eyes narrowed, focusing on the attacker's location.

Standing exactly where he had been moments ago—

Was a white-haired boy, holding a black-bladed sword infused with dark magic.

Kiba Yuuto.

"Su Hai-kun, What Are You Hiding?"

Rias watched the exchange with growing amusement.

A subtle smirk appeared on her lips.

"A samurai sword… and such quick reflexes…"

"It seems Su Hai-kun has a little secret, doesn't he?"

Her eyes gleamed with intrigue.

She subtly analyzed the Sun Blade in Su Hai's hand, wondering—

Was this his Sacred Gear?

Su Hai Understands – This Was a Setup

Su Hai let out a deep sigh, keeping his blade raised.

"I see…"

"So this was your plan all along, Rias?"

"Shouldn't classmates get along and support each other?"

"Attacking me like this isn't exactly friendly, you know?"

By now, he fully understood—

This was a deliberate test.

Rias must have suspected something about him and arranged this setup to confirm it.

But how?

"My system only awakened yesterday. My powers are new… So how did she notice?"

Su Hai frowned internally.

No one should have had any reason to suspect him.

Yet, Rias had connected the dots and acted so quickly.

Unfortunately, Rias ignored his words and simply gestured to Kiba to continue.

She wanted answers—and the best way to get them was through battle.

A Duel of Swordsmen – Kiba vs. Su Hai

Kiba nodded respectfully, raising his cursed sword once more.

"Su Hai-kun, I apologize in advance—"

"But as per the President's request, I must test your skills."

His voice was polite, but his intent was clear—he was taking this seriously.

"Breath of Thunder… Sevenfold Thunderclap and Flash!"

Su Hai muttered under his breath, his eyes sharpening as his entire body tensed like a coiled spring.

A Storm of Lightning

Kiba launched forward, his blade cutting through the air, aiming directly for Su Hai's vitals.

But—

The moment Kiba moved, Su Hai's vision slowed.

Every detail—Kiba's footwork, his breathing, the angle of his swing—became clear.

With perfect timing, Su Hai's knees bent slightly, his hand gripping his sword hilt—

Then, in a flash of golden lightning, he vanished from sight.

"So fast!"

Kiba's eyes widened in shock, his grip tightening instinctively.

Unmatched Speed

Anticipating an attack, Kiba raised his sword to block—

But at the last second, Su Hai disappeared again.

"He changed direction?!"

Before Kiba could adjust, Su Hai had already reappeared beside him, blade poised to strike.

In desperation, Kiba slammed his hand against the ground, channeling his Sacred Gear's power.

In an instant, a dozen massive cursed swords erupted around him, forming a barrier of blades.

For a moment, he felt relief—believing he had successfully blocked the attack.

But—

"Tch—!"

A bright yellow streak of light flashed through the air.

The next second—

A single, precise sword stroke shattered the cursed swords, cutting straight through Kiba's defenses.

Before he could react, the cold steel of Su Hai's Sun Blade rested lightly against his throat.

Kiba stood frozen, realizing his defeat.

"Su Hai-kun… You Win."

For a brief moment, there was silence.

Then—

Kiba let out a chuckle, smiling bitterly.

"Su Hai-kun… I lost."

He had already known Su Hai was skilled.

But he never expected this level of precision and speed.

Even with his Sacred Gear's abilities, he had been completely outmatched.

A New Power – Unlocking Magic

"Ding!"

"Congratulations, Host! You have unlocked a Two-Star Golden Egg!"

"Reward: A small amount of Magic Power."

The moment Kiba conceded, a warm energy flowed into Su Hai's body.

It settled deep within his abdomen, a faint yet noticeable source of power.

Su Hai's First Step into Magic

For the first time, Su Hai possessed magic power—

A crucial energy in this world, known by different names across various factions:

Mana, Ki, Divine Power, Demonic Energy…

But fundamentally, it was all the same—the fuel for powerful abilities.

Su Hai clenched his fist experimentally, feeling the new energy pulse within him.

A small smirk formed on his lips.

"This is exactly what I needed."

Now, with this magic power, he could finally—

Unleash the true power of the Sword of Oath Victory.

Rias' Offer – Join Me

Before Su Hai could reflect further, a sound broke his focus—

Clap. Clap. Clap.

A slow, deliberate applause echoed through the clearing.

"That was spectacular, Su Hai-kun."

Rias and Akeno approached, admiration clear in their eyes.

Su Hai sheathed his blade, exhaling deeply.

"If that's all, I'll be leaving now."

But just as he turned to go, Rias spoke—

"Su Hai-kun—be mine."

Su Hai froze, stunned by her words.

Even Kiba and Akeno didn't look surprised—as if they had expected this.

The Truth of This World

Rias stepped forward, her expression turning serious.

"Su Hai-kun, after what you saw last night, you must understand—"

"This world is not what it seems."

Then, without hesitation—

She spread her wings.

Dark, bat-like demonic wings unfurled from her back, displaying her true nature.

Her blue eyes locked onto his.

"I am Rias Gremory, a High-Class Devil."

"And I want you in my Peerage."