The Dragon’s Oath

Morning broke gently over Kuoh Town, its golden rays spilling through the tall windows of Issei Hyoudou's chamber. Light danced across tangled silken sheets, wrapped around two bodies locked in an intimate embrace—where warmth came not just from the sun, but from unbridled desire.

Akeno Himejima straddled Issei with feline grace, her raven hair cascading like midnight silk across flushed skin. Beads of sweat shimmered on her bare body as she moved in a slow, reverent rhythm. Her back arched, a quiet gasp escaping her lips—each exhale a whispered offering.

"You're insatiable in the morning, my Lord," she moaned, voice a heady blend of teasing and surrender.

Issei chuckled, his golden eyes half-lidded, hands gripping her hips with practiced control. "Just following orders."

Akeno leaned down, her lips grazing his neck. "And doing it so very well."

The room pulsed with the scent of sex and rising power—an atmosphere thick with both pleasure and purpose. As their bodies neared climax, a chime rang clear in Issei's mind.

[System Notification: New Tasks Acquired.]

[Task One: End Rias Gremory's Engagement with Riser Phenex.]

[Rewards: 50,000 SP, Gremory Loyalty Passive, Bond-Linked Evolution unlocked and Mutated Evil Pieces – Allows peerage members to evolve into dragons.]

[Task Two: Claim the Two Gremory Sisters.]

[Rewards: Destruction Magic (Lucifer Variant) & Familiar Summoning Scroll.]

[Task Three: Assist in Training Rias and Her Peerage.]

[Rewards: Custom Sacred Gear Blueprint: 'Forgeheart – Origin Bloom' and Personal Training Room — Fusion Type: Danger Chamber (X-Men Protocol + Hyperbolic Time Chamber).]

[Bonus Objective: Forge a weapon worthy of a Dragon Emperor.]

[Ddraig: Hah! That last one sounds like a challenge. You'd better not disappoint.]

"Looks like my schedule just got busier," Issei muttered.

His smirk faded, mind sharpening as desire gave way to strategy.

"Damn system," he muttered. "Where the hell are these tasks coming from?"

[From your King's—Rias Gremory's—deepest desire. She has formally submitted her request to join your harem. She also consulted her elder sister, the Maou Lucifer.]

Akeno, ever perceptive, lazily traced a finger down his chest. "What's the little voice in your head whispering now, Master?"

Issei exhaled. "Rias wants in. And she brought her sister into the loop."

Akeno's violet eyes sparkled. "So, the princess is ready to kneel. About time. She'll make a fine second."

With sudden force, Issei flipped their positions, seizing control. Their pleasure surged—fast, furious, final. When it passed, Akeno lay draped across his chest, completely spent.

"…Also," he muttered, eyes on the ceiling.

[Yes, host?]

"I can't keep calling you 'System' forever. It's getting old."

[Would you like to designate a name for this interface?]

"Yeah. Something fitting." He paused. "Mission Command?"

[Denied. You are not a space pilot, host.]

"…Queen?"

[You already have one in bed with you.]

"Fair. Oracle?"

[A touch dramatic, but acceptable. Still, consider alternatives.]

He sighed. "Fine. Eden. Feels right."

[Accepted. System designation updated to: Eden.]

"Eden, huh?" Akeno murmured. "Sounds divine."

[Speaking of divinity—your Evil Pieces are not standard.]

"…Huh?"

[A surprise awaits. One that will reshape your peerage.]

"Better not mean they turn into furries."

[Unlikely. More like… monsters.]

Issei smirked. "Good."

⸻

Morning – Hyoudou Residence

The rich scent of brewed tea mingled with grilled fish and steamed rice as Mikki Hyoudou set the breakfast table, humming softly. Gorou Hyoudou sat behind the morning paper, brow furrowing at the unusual sound of footsteps descending the stairs.

Akeno Himejima, perfectly composed in her pristine Kuoh Academy uniform, stepped gracefully into the room behind Issei.

"Good morning, Hyoudou-san, Hyoudou-sama," she greeted, bowing with elegant formality. "Thank you for your hospitality."

Both parents froze mid-motion.

Mikki's jaw worked soundlessly as she stared between her son and the impossibly beautiful girl. Gorou's newspaper crinkled in his tightening grip.

"U-Uh, Issei…" Mikki managed, voice rising a full octave. "W- Who is this young lady? And—wait, does Rias know about her?!"

Issei scratched the back of his head, offering a sheepish grin. "Yeah, yeah, she knows. It's… complicated, but she approves."

"Approves?!" Gorou choked his face cycling through disbelief, horror, and awe. "What is she, your mistress?!"

Akeno's lips curled in amusement. "I am his Queen. By both peerage standing and personal vow."

Mikki nearly fainted. "Queen?!"

"It's a devil thing, Mom," Issei tried to explain. "We're working it out."

After a few moments of hyperventilating, Mikki shakily grabbed her phone. "I… I'm calling Azazel."

⸻

Grigori HQ – Azazel's Office

The Fallen Governor lazily scrolled through a stack of field reports when his phone buzzed.

"Yo, Mikki. What's up? You don't usually call me this early."

Mikki's voice came rapid-fire. "Azazel! Do you know a girl named Akeno Himejima?!"

Azazel blinked. "Uh, yeah. Why?"

"Because she's here! At our house! She stayed over! And Issei and her—" Mikki's voice dropped to a scandalized whisper, "they gave each other their first times!"

Azazel choked on his coffee.

"And she's calling my son 'Master!' Explain yourself!"

Before he could even react, a new voice cut in.

"Why are you bringing up my daughter?" Baraqiel's thunderous voice boomed as he strode into Azazel's office.

Azazel sighed and put the call on speaker. "Because your daughter spent the night at my godson's house, did the deed, and is now calling him Master."

Silence.

Then Baraqiel's eyebrow twitched. "…Repeat that last part."

"She's calling him Master."

Another long pause.

Then a heavy exhale from Baraqiel. "Well, damn. Your godson must've activated her masochist side. Tamed one of the Himejima women? That's either impressive… or suicidal."

Azazel snorted. "Knowing Issei, probably both."

Mikki's horrified voice crackled through the speaker. "WHAT DO YOU MEAN MASOCHIST SIDE?!"

Azazel groaned. "Look, Mikki—Akeno's mother was Shuri Himejima, from one of the Five Principal Clans. The Himejima women are infamous in certain circles… sadistic tendencies run in their bloodline. If Issei's gotten her to willingly submit and call him Master, it means he's hit a, uh… special nerve."

Baraqiel pinched the bridge of his nose. "I need a drink. Boss, I'm taking a personal day I need time to process my baby girl growing up."

Gorou finally spoke up, still in shock. "My boy… my son… got a supernatural sadist to call him Master?"

Azazel chuckled darkly. "Congratulations. Your son's officially playing in the big leagues now."

He leaned back in his chair, grinning. "I might need to go meet this godson of mine properly. Maybe take him out like I did when you were in college, Gorou."

⸻

Later That Morning – Gremory Manor

The Gremory Manor stood like a citadel of nobility and infernal might—crimson towers carved from enchanted marble and adorned with sigils that shimmered like starlight. Inside, the air was perfumed with roses and power, and legacy hung heavy on every wall.

In a sunlit drawing room, two red-haired women sat opposite each other—sisters, yet so vastly different.

Sirzaria Lucifer, the current Maou, bore a striking resemblance to her mother, Venelana Gremory. Her long crimson hair cascaded in thick, commanding waves, and her features were regal: sculpted cheekbones, piercing scarlet eyes, and lips that wore equal parts command and amusement. Her armor gleamed black and gold, shaped to her tall, powerful figure—more queen than a warrior, yet both.

Opposite her sat Mio Gremory, the middle sister. Five years older than Rias and far less formal than Sirzaria, Mio's beauty was explosive—voluptuous, wild, and defiant. Her red hair flared like fire, tied back with a dark ribbon, and her violet eyes sparkled with curiosity. She wore a sleek bodysuit with a crimson half-cape—less militaristic than her elder sister, more provocative, more battle-ready.

Rias, by contrast, sat stiffly, her beauty more youthful and unsure. Her sapphire eyes darted between her sisters, seeking guidance.

"You're serious?" Rias asked, voice trembling. "You both support this? Me becoming… his?"

Sirzaria leaned forward, her gaze both comforting and commanding. "Rias… I've seen many devils rise to power. But Issei is something else entirely. He's not just strong—he's destined. Dragons don't kneel to kings. They become them."

Mio smirked, swirling wine in her glass. "Honestly, I thought you'd choose a weaker man. But Issei? He's dangerously fun. I approve."

Rias swallowed. "But it's a harem. Isn't it wrong to just… give myself away?"

"You're not giving anything away," Sirzaria replied. "You're choosing. And in choosing Issei, you're aligning with someone who could change the Underworld itself. Do you want to fight beside him? Or be left behind?"

Rias looked down. "He's different. He doesn't chase me. He doesn't need me…"

"And that's why you want him," Sirzaria said, smiling. "Tell him the truth. About your engagement. About your wish to be his. And when the time comes, let him meet me. I want to see what kind of dragon dares to charm my sweet little sister."

Mio leaned in with a predatory grin. "I can't wait to meet my baby sister's first crush."

"He's not a crush!" Rias screamed, her voice cracking. "He's more than that!"

Sirzaria raised an eyebrow, smirking. "So what is he, Ri-Ri?"

"I… I don't know!" Rias shouted before storming from the room.

Mio chuckled into her wine. "Adorable."

Later That Morning – Rias's Private Room

Golden light filtered through gauzy curtains, painting Rias Gremory's chamber in hues of warmth and longing. She lay atop her bed still in uniform—blouse crisp, skirt immaculate, crimson jacket unfastened. Yet her expression was anything but composed.

A soft knock.

"Come in," she called.

Akeno stepped inside with quiet grace. Her uniform was once again pristine, but the morning's glow lingered in her cheeks and the satisfied gleam in her eyes.

"You've been quiet since the meeting," Akeno noted, settling beside her.

"I've been thinking," Rias replied. "About you. About him."

Akeno smiled faintly. "Yes—it happened. Yes—I was his first."

Rias turned toward her, sapphire eyes uncertain. "And you don't feel… guilty?"

"Only if I had lied," Akeno said gently. "But I didn't. You always knew. You were just waiting for permission—from yourself."

Rias exhaled. "I was. I wanted him to chase me. To prove I mattered."

"And instead," Akeno whispered, brushing her fingers through Rias's crimson hair, "he's becoming the one we fight for."

"What does it feel like?" Rias asked. "Being his?"

Akeno's voice softened. "Like standing in the heart of a storm. He's wild, powerful… overwhelming. But I've never felt safer. He is also bigger than all my toys so you might want to prepare for that."

Rias blushed before sitting up slowly. "He'll change us."

"He already has."

Silence. Fragile, intimate.

Then Rias laughed quietly. "Don't be smug when it's my turn."

"I'm always smug," Akeno teased, kissing her friend's cheek. "But I'll try."

"No, you won't."

"True."

Akeno rose, adjusting her collar with flair. "So, when's the confession? Tonight? Chemistry class? Over a Bunsen burner?"

"Akeno!"

She smirked. "Pounce soon. Fewer rivals to stab."

"You're impossible."

"And you," Akeno called as she exited, "are in love with a dragon."

Later That Day – Kuoh Academy

As the afternoon sun dipped low, Issei and Akeno walked side by side under golden skies. Behind them, Rias followed—regal as ever, but her eyes betrayed the weight she carried.

"So," Akeno asked casually, "how do you want to handle Rias?"

"Directly," Issei said. "She'll come to me tonight. But before that—we need to talk about Asia."

"The nun girl?" Akeno's tone darkened.

"She has Twilight Healing. Raynare's watching her. We move tonight, or she dies."

"Then we act tonight, "…her voice sharp as cut glass, thunder humming beneath her skin."We get her to join as Rias Bishop and our five-person family"

"She's worth it."

Akeno considered him. "Rias should know. Framing this as 'balance maintenance' might ease things."

"Good call. Oh—and one more thing," Issei added, his tone lighter. "Do you think Rias could help me get a forge built?"

Akeno blinked, then smirked. "A forge? Since when did you take up smithing?"

"After the duel with Kiba," he shrugged. "System dropped some blacksmithing knowledge on me. Figured it'd be smart to make my own weapons and gear. Maybe even forge gifts for my peerage."

Akeno's grin widened. "I swear, Issei… you're becoming a proper warlord. She'd build you a mountain if you asked her shirtless and probably guard it in a silk robe." You'll have your forge."

"Not just any forge," Issei mused, his mind already racing. "I'm thinking enchanted metals. Niflheim frost-iron. Azoth steel. Maybe something ancient—like Orichalcum, if I can find it."

Akeno whistled. "Damn, aiming high already."

"Nothing less. Eden," he called out internally.

[Yes, my wonderfully demanding host?] the system purred, a teasing lilt to her voice.

"Start compiling a list of rare ores, alloys, and forging materials in both the Underworld and the human world. Priority on ones with high energy conductivity and resilience against divine-class artifacts."

[Ooh, getting ambitious, aren't we? I'll get right on it. And don't worry — I'll make sure to color-code them by how likely they are to kill you while mining.]

Issei snorted. "Cute."

Akeno glanced at him. "You really are planning to reshape the board."

"I don't want to play on someone else's board," Issei replied. "I will create my own."

Kuoh Town – Nightfall

The moon cast a silver glow over Kuoh Town, its light filtering through the windows of the Occult Research Club. Inside, the atmosphere was tense, charged with anticipation.

Issei Hyoudou stood at the center of the room, his gaze fixed on the glowing summoning circle. Beside him, Akeno Himejima watched silently, her expression unreadable. Rias Gremory entered, her steps hesitant but determined.

"Issei," she began, her voice steady, "I've made my decision. I want to join your harem, "If I'll have you me?" Issei stepped forward, the circle's glow reflecting in his eyes. "I told you, Rias — I don't chase. I claim."

Issei turned to face her, his golden eyes meeting her sapphire ones. "You've always been mine. You just had to accept it." 

Tears welled up in Rias's eyes, but she blinked them away. "I want this, but I need to be free. The engagement…"

"Riser," Issei let out a low dragon-like growl.

Rias nodded. "The Rating Game. Win with me, and everything I am is yours."

"I will," he said, his voice firm. "I'll fight beside you always all of you."

"Always."

She moved closer, her hand reaching out to touch his. "Then help me. Not just with Riser. With everything. I want to belong to you, but also stand beside you."

He cupped her cheek gently. "Then let us start now. We've got someone to save."

"Asia," Rias breathed. "Is she in danger?"

"We move tonight," Issei said. "Raynare's closing in."

"Then we go together," Rias agreed. "And Asia… you want her as your Bishop?"

"She deserves strength. And safety. My dear king, I want her as yours."

"She'll have both."

Akeno stepped forward, a smirk playing on her lips. "You sound like his Queen already, Rias."

Rias looked at her best friend. "Not yet. But I will be."

[Eden Log Updated.] 

[Task Confirmed: Rescue Asia Argento.]

[Optional Objective: Eliminate Raynare.]

[Bonus Reward: Divine Dragon Scale – First Layer Unlocked.]

[Note: Failure to complete the mission will forfeit pending Quetzalcoatl Soul Reward. Replacement prize: Lesser Wyrm-Class Dragon Soul.]

[No pressure. But seriously… don't screw this up.]

Issei's eyes narrowed. "Noted."

[Warning: Host entering divine conflict zone. Radiant and demonic energies will clash. Recommendation: Prepare emotionally aligned party.]

"I'll need all of you with me," Issei said aloud.

"You have us," Akeno replied, lightning sparking at her fingertips. "Let's give those fallen a night to remember."

"Rias," Issei added, eyes locking with hers. "When this is over—when you're free—I'm going to mark you. Like I did Akeno."

Her blush deepened, but she stood tall. "Win with me first. Then… everything I am is yours."

As they prepared to leave, Issei's thoughts turned to Asia. He remembered her gentle smile, her unwavering kindness.

"She's too kind for this world," Issei muttered. "But I'll make her strong enough to survive it."

With resolve burning in their hearts, the trio stepped into the night, ready to face whatever challenges awaited them.

Raynare paced the altar, eyes sharp and calculating.

"Prepare the ritual. The nun will die by dawn," she ordered.

From the shadows, a chained figure trembled—Asia Argento, her tear-streaked face filled with fading hope.

Suddenly, her golden eyes widened. Somewhere, far away, a presence burned into her heart like the first light of sunrise.

And she frowned. 

"What is this power this feeling."