The crimson flash dissipated, leaving the Gremory peerage inside an exact dimensional replica of Kuoh Academy. The sky outside had an unmistakable and eerie greenish tone, illuminated by an artificial moon.
Grayfia Lucifuge's magical voice echoed from the heavens, covering the entire battlefield.
"The Rating Game between the House of Gremory and the House of Phenex has begun."
Immediately, Rias Gremory assumed her role as King. She stood at the center of the replica of the Occult Research Club, her Diadem of Annihilation glowing faintly, and began deploying a holographic map of the academy over the table.
"Everyone, listen. This is the plan," Rias began, her tone overflowing with authority and confidence. "Kiba, you'll use your new supersonic speed to set traps in the forest and isolate the enemy Pawns. Koneko, you'll be our physical vanguard. Don't hold back. Akeno and I will provide heavy cover fire. Issei, stay alert and look for opportunities to use the Boosted Gear. And Kaiju... you'll be our ace in the hole, intervening if Riser decides to..."
"Sorry to ruin your Napoleon Bonaparte moment, tomato head," a drawn-out voice interrupted from the back of the room.
Rias stopped her speech. Everyone turned their heads to look at Kaiju. True to his nature, Kaiju had already made himself comfortable on the base's sofa, reclining with his arms crossed behind his head.
"You've improved a lot. Your new weapons are lethal, and your attitude stopped being pitiful," Kaiju admitted with a yawn. "But let's be brutally realistic. Riser has fifteen pieces. You have five. He's a pure-blooded devil with near-instant regeneration, vast combat experience, and zero scruples. If he attacks seriously from the first second and decides to send all his pieces in a suicidal assault to wear you down, you'll lose through sheer math and endurance."
Issei swallowed, going pale. "T-Then... what do we do, Kaiju-sensei? Are you going to go out there and erase the whole academy with that Black Eye of yours?"
"No. I said I would only supervise and crush whatever was necessary, but the main victory has to be yours." Kaiju sat up on the sofa and slipped a hand into his pocket. "That's why I brought my 'accessories.'"
The young god pulled out the two bright yellow spherical earrings he had registered in front of Grayfia. With a quick flick of his wrist, he tossed one to Rias.
The redhead caught it in midair, looking at the small jewel with curiosity. "What is this, Kaiju?"
"It's a Potara Earring," Kaiju explained, standing lazily. "A divine fusion artifact. If two people each put on one earring on opposite ears, their bodies and souls temporarily fuse into a single being. And the beauty of this is that the power doesn't add together; it multiplies."
Rias, Akeno, and Kiba widened their eyes, immediately understanding the terrifying tactical implications of such an object.
"That's my plan for you, Crimson King," Kaiju continued, pointing toward the Vice President. "Rias, I want you to use that earring to fuse with Akeno. The dark annihilation of your bloodline combined and multiplied by her holy lightning storm. You'll create a warrior with power so absurdly high that Riser and his flames will look like a snuffed-out candle in the middle of a hurricane."
Akeno smiled, her eyes shining with anticipation at the thought of sharing such a level of power with her best friend. "Ara, ara... that sounds like guaranteed victory."
"How exactly does it work?" Rias asked, holding the earring carefully, fascinated by the idea.
"It's idiot-proof. You just have to put it on," Kaiju said. To illustrate his point, he took the other earring left in his hand and brought it toward his head. "For example, if you put yours on your right ear... the other person has to put theirs on the left ear. Just like this."
Kaiju hooked the yellow earring onto his own left ear with a click, looking at her to see whether she had understood the explanation before taking it off and giving it to Akeno.
But Rias Gremory was not processing the tactical explanation.
From the moment Kaiju put the earring on, the redhead's mind—heavily influenced by her immense affection, her extreme trust in him, and the blindness of being focused on the "lesson"—acted on pure reflex. She saw him put it on the left. Her brain immediately registered: I have to put mine on the right.
With a warm smile and unshakable determination, Rias raised her hand and hooked the Potara Earring onto her right ear.
Click.
The silence in the clubroom lasted exactly half a millisecond.
The two Potara Earrings, the one on Kaiju's left ear and the one on Rias's right ear, emitted a flash of yellow light so intense it temporarily blinded Issei and Kiba.
Kaiju blinked. His divine brain, capable of processing the birth of galaxies, froze before the magnitude of the human error he had just witnessed.
He felt an impossible gravitational pull, an absolute and undeniable cosmic force dragging him directly toward the President.
"WAIT, NO!" Kaiju shouted, losing his stoic mask of laziness for the first and only time. His eyes bulged with absolute horror. "I SAID WITH AKENO! NOT WITH MEEEEE—!"
"Huh? K-Kaiju!" Rias exclaimed, realizing her mistake far too late when she felt her feet lift off the ground, pulled toward him like a magnet drawing steel.
SWHAAAASH!
Before the stunned gazes of Akeno, Koneko, Kiba, and Issei, the bodies of the lazy God of Destruction and the heiress of the Gremory Clan slammed together violently in the center of the room, wrapped in a pillar of divine and demonic light so colossal that it made the entire pocket dimension tremble.
The light was not a single color. It was a violent, chaotic vortex where the brilliant gold of Potara magic desperately tried to merge two concepts that should never have been mixed. On one side, the dark crimson aura of Rias's Annihilation. On the other, the infinite, overwhelming, unfathomable whiteness of the Creator's divine energy.
The floor of the Kuoh Academy replica began shaking with the intensity of a magnitude ten earthquake. The building's windows shattered into a thousand pieces simultaneously. Kiba drove his crystal swords into the ground to avoid being blown away, while Akeno conjured a shield of light and lightning to protect Koneko and a terrified Issei.
"[HYOUDOU! TAKE COVER, DAMN IT! THE DIMENSIONAL FABRIC IS TEARING APART!]" Ddraig roared inside the brown-haired boy's mind, his voice sounding sharper and more panicked than Issei had ever heard it. The legendary dragon was literally curled into a fetal position inside his jewel. "[That energy... makes no sense! It's a monster giving birth to another monster!]"
Inside the pillar of light, a biological and cosmic miracle was happening in fast motion.
The Potara Earrings were designed to fuse two individuals into one perfect being, balancing their souls. But here, balance was a cruel joke. Kaiju's soul was an infinite, bottomless ocean; Rias's soul, though immense by demonic standards, was barely a crimson drop of water falling into that abyss.
The universe did the math. Faced with the abysmal and incalculable difference in power, the dominant physical trait crushed any attempt at femininity in the final result. The fusion took Kaiju's male biology as the base template, devouring Rias's anatomy and rewriting it.
However, unlike the original Potara in the Dragon Ball universe—which usually left the stronger individual's personality in command or created a blend of both—Kaiju's conceptual alterations to his own objects caused an anomaly. It was not Kaiju in the driver's seat. It was not Rias taking control.
It was an entirely new soul. An identity that had just opened its eyes for the first time, fueled by demonic royalty's pride and the absolute invincibility of a god.
The pillar of light burst like cosmic glass, sending out a golden and crimson shockwave that swept across the pocket dimension's green sky, instantly dyeing it a deep and threatening purple.
When the dust and light dissipated, a male silhouette stood at the center of the crater that had once been the clubroom floor.
The lazy teenage god in pajamas was gone. Before the Gremory peerage now stood a tall young man with an athletic build and perfectly defined muscles radiating pure power. His hair was wild and spiky, jet-black with bright crimson highlights at the tips, waving upward from the sheer energy his body released.
He wore an outfit that was strange yet elegant: dark martial arts pants, light boots, and an open dark crimson jacket with no shirt underneath, showing off a toned chest. The Potara Earrings hung from his ears, while on his forehead rested a fused version of the Diadem of Annihilation, now transformed into a thin mithril crown that looked tattooed onto his skin.
The warrior opened both eyes, revealing two identical irises that were a hypnotic, swirling blend of Rias's sapphire blue and Kaiju's deep brown.
The new being raised his hands, flexing the fingers covered by black leather fingerless gloves. He observed his own body, rolled his neck with a crack of his vertebrae, and a wide, arrogant, ridiculously confident smile spread across his face.
"YOSHA!" the warrior shouted, clenching his fists enthusiastically as a blazing aura surrounded him. "Well, well! There was a little miscalculation in the instructions, but I'm not complaining at all! Damn, this body feels good!"
Akeno lowered her shield, breathing unevenly, a blush forming on her cheeks before the imposing, masculine, and overwhelming figure standing in front of her. "K-Kaiju-kun...? Buchou...?" the Thunder Priestess stammered.
The warrior turned toward her, winked with a shamelessness Kaiju would never have shown, and released a vibrant laugh.
"Kaiju is taking a nap in the back of this soul, gorgeous. And Rias is part of me now. I'm the perfect combination of the Almighty Creator and the Princess of Ruin! Hmmm..." He brought a hand to his chin, thinking dramatically. "Rijuka? No, sounds like a juice brand. Call me... Raiju. Yeah, that has way more style."
Raiju crossed his arms, widening his smile. His personality was a Molotov cocktail: the arrogance and pure pride of the Gremory heiress combined with the crushing confidence and playful sarcasm that Kaiju normally repressed beneath his laziness. He was boastful, shameless, and had an immense desire to show off.
Paradoxically, the fusion had resulted in a strange mathematical limitation. In theory, a Potara fusion multiplies power (A x B). But Kaiju possessed near-infinite power, while Rias was mortal. Rias's mortal body, upon fusing, acted as a physical filter, a biological funnel incapable of processing infinity.
The result was that Raiju, this new entity, possessed only one fourth—twenty-five percent—of Kaiju's total unrestrained power. In technical terms, the fusion was weaker than the original Kaiju at his maximum capacity.
But there was one terrifying detail.
Kaiju spent one hundred percent of his life suppressing his power down to a pitiful percentage. Raiju, being a new, boastful personality who loved showing off, was not suppressing any of that twenty-five percent.
That twenty-five percent of raw divinity flowed freely, cracking the space-time of the Phenex House's pocket dimension. The air was so heavy that Issei and Kiba were forced to their knees, gasping for oxygen. Kilometers away, in the replica of the Student Council building, Riser Phenex and his entire peerage fell to the floor, crushed by a gravitational and magical pressure that had no logical explanation.
"Oops, my bad. Guess I'm leaking a bit of my awesomeness," Raiju joked, suppressing the pressure of his aura just enough for his companions to breathe again. "Whew, this energy is begging to be used."
Koneko stared at him with her cat ears stiff, completely paralyzed. "R-Raiju-senpai...?"
"The one and only, kitten," Raiju smiled, cracking the knuckles of both hands with a metallic sound. "All right, listen up, team. The original plan was for you to play while I watched. But as it turns out, now I'm the King and the strongest Pawn at the same time. And I'm incredibly bored."
Raiju turned toward the shattered door of the clubroom, looking in the direction of the enemy base. His two-colored eyes shone with a mixture of playful sadism and crushing superiority.
"Akeno, Kiba, Koneko, Issei... take a break," Raiju ordered, floating a couple of centimeters above the ground, his voice resonating with a confidence that left no room for argument. "Stay here and prepare some snacks. I'm going to look for an immortal little bird and pluck his feathers one by one. I'll be back in five minutes. And that's being generous."