---
⛅ Afternoon – Gremory Mansion, Training Grounds
The skies above the Gremory estate glowed a deep orange, casting a surreal ambiance across the vast training fields nestled behind the mansion. Kaizen stood in the center, his eyes closed, focusing entirely on his inner world. His body radiated quiet tension, a coiled storm just beneath the surface.
After the events of the rescue operation and Kaizen's direct clash with the stray devil faction, the group had returned to the Gremory mansion to regroup. But there was no rest. Not for Kaizen. Not when the lines between friend and foe grew blurrier by the day.
His fingers curled inward, feeling the faint hum of energy pulsating through his limbs. His Gearflow Intuition had evolved again—sharper, more refined. It now not only allowed him to analyze energy flows but to absorb, redirect, and even mirror certain techniques.
Lightning crackled to life in his right hand, not his own… but a perfect mimicry of Akeno's.
Nearby, Akeno stood with arms crossed, watching him with a blend of curiosity and admiration. "I see you've figured out how to copy my magic," she said, raising a brow, "Are you sure you're not secretly a devil?"
Kaizen exhaled, opening his eyes. "No, but I've learned how to adapt. Your power has a rhythm. A frequency. My ability reads it like a score."
She smiled, stepping closer. "Then maybe you're the perfect instrument."
Their moment was cut short as a familiar presence arrived. Rias Gremory, dressed in her combat attire, approached with swift, deliberate steps. "Kaizen, come with me. We have visitors."
"Visitors?" he asked.
"Not enemies," she clarified. "But they may not be friends either."
---
🏛️ Main Hall – Gremory Mansion
Kaizen entered the grand hall behind Rias and was met with the sight of two new arrivals seated across from Sirzechs Lucifer himself. One of them bore the armor of the Church, her silver hair and piercing blue eyes standing out against the scarlet tapestries.
"Kaizen, this is Irina Shidou," Sirzechs introduced. "And the man next to her, Xenovia Quarta. Representatives of the Church's anti-fallen angel unit."
Irina offered a small nod. "We've heard about you, Kaizen. A being not aligned with Heaven, Hell, or Grigori. Your existence… concerns some."
Kaizen narrowed his eyes. "And yet you're here, talking instead of fighting."
"We're not here to declare war," Xenovia said flatly. "We're here to investigate the recent disruption in dimensional borders. We believe someone from our side may be collaborating with the stray devils you encountered."
A hush fell over the hall.
Rias folded her arms. "Are you saying there's a mole in the Church?"
"Yes," Irina confirmed. "And we believe Kaizen may be one of their targets."
Kaizen's mind raced. So the enemy wasn't just gathering power—they were gathering reach. Multiversal reach.
---
🌃 Later – Mansion Balcony
Night had fallen. Kaizen stood on the high balcony, watching the stars shimmer against the velvet sky. Beside him stood Rias, her presence calm but troubled.
"You've become something more than just a traveler, Kaizen," she said softly. "You're a linchpin. A fixed point. I don't think you realize how important you are to this war."
Kaizen kept his gaze on the sky. "I don't want to be anyone's linchpin. I just want to keep the ones I care about safe."
Rias turned toward him, eyes reflecting the stars. "Then you'd better start acting like a king, not just a protector."
That sentence struck something deep within him.
He glanced at her. "You think I could be a king?"
She smiled. "No. I know you could be."
Before either could say more, a burst of demonic energy exploded from the east side of the estate.
Boom.
Both turned toward the noise. Akeno's voice rang through the hallway.
"We're under attack!"
---
🌌 Gremory Estate – Attack and Battle
The shockwave of the explosion rocked the ground beneath Kaizen's feet. The once serene Gremory estate was suddenly a battlefield — shadows and light clashing beneath the crimson twilight.
Kaizen's eyes flared with determination. "Stay here. I'll handle this."
Rias grabbed his arm, her grip firm. "No. We fight together."
Before Kaizen could protest, the other familiar faces of the household appeared — Akeno, Koneko, and even Issei, all moving swiftly to their battle positions.
The attackers emerged through the shattered garden gate — a squad of cloaked figures, their auras dark and twisted, marked by an unnatural flicker that made them seem… otherworldly.
Irina and Xenovia drew their swords, their holy light flaring to life.
Kaizen clenched his fists, feeling his Gearflow Intuition spike wildly. These weren't mere stray devils; they were corrupted by something else — a deeper, more dangerous power.
One of the cloaked figures stepped forward, revealing a tall man with jet-black hair and eyes that burned a sickly green.
"Kaizen," he sneered, voice like gravel. "You've meddled too much. The Church's enemies will cleanse this world of your interference."
Kaizen recognized the voice instantly. Lucifer's shadow, a fallen Grigori agent bent on multiversal chaos.
Without hesitation, the battle erupted.
---
⚔️ Clash of Powers
The courtyard became a tempest of flashing steel and crackling energy. Kaizen and the man, whose name was revealed as Zerath, clashed head-on, their powers colliding in a shower of sparks.
Zerath unleashed dark energy blasts, twisting and corrupting the very air around them. Kaizen responded with his mirrored lightning, twisting the attacks back with refined precision.
The fight was brutal and intense. Every moment tested Kaizen's evolving abilities.
His Gearflow Intuition now allowed him to anticipate not just physical moves, but the underlying flow of enemy magic and intent. With a swift mental command, Kaizen absorbed a blast of corrupted energy and converted it into pure lightning that arced toward Zerath's defenses.
"Impressive," Zerath growled. "But you've only scratched the surface."
Behind Kaizen, Rias and Akeno engaged the other cloaked fighters, their coordinated attacks a display of deadly elegance and raw power.
---
🔥 Unleashing New Power
Kaizen's heart pounded as he realized Zerath's aura was expanding, feeding on multiversal energy. The battlefield itself seemed to tremble under the pressure.
Drawing a deep breath, Kaizen called on the core of his being — the power gifted to him by his multiversal journeys.
"Gearflow Ascendance," he whispered.
His body surged with golden light as ancient symbols burned along his arms and chest. The world slowed, time folding slightly around him, allowing him to perceive multiple possible outcomes of each attack.
His lightning blazed brighter, more potent than ever, crackling with a force that seemed to tear at the very fabric of reality.
With a shout, Kaizen surged forward, breaking through Zerath's defenses with a burst of raw power.
---
🌠 Aftermath and Reflection
The cloaked invaders retreated, their forces broken and scattered.
Kaizen stood amid the wreckage of the garden, chest heaving but victorious.
Rias approached, placing a hand on his shoulder. "You did well."
He met her gaze. "This is far from over."
Irina and Xenovia nodded solemnly. "The Church will not abandon its hunt."
Kaizen looked out toward the horizon, the weight of the multiverse pressing on him.
He was no longer just a traveler. He was a fighter. A leader. A force standing between countless worlds.
---
🌙 Night Falls on the Gremory Estate
The battle had left scars—shattered marble, scorched earth, and lingering tension heavy in the cool night air. The estate was quiet once more, but the wounds were far from healed.
Kaizen paced slowly near the main hall, the adrenaline of the fight fading into a simmering resolve. The glow of the moon cast long shadows across the grounds, shadows that whispered of dangers lurking still.
Rias stood beside him, her crimson hair catching the moonlight like fire.
"We've seen only a fraction of Zerath's power," she said softly. "The Church's hand runs deeper than I imagined."
Kaizen nodded, his thoughts racing. The fallen Grigori's intentions were clear—eliminate interference and claim dominion over the multiverse's fragile balance.
"We need answers," Kaizen said. "And allies."
---
🗝 Secrets Unveiled
Inside the study, Kaizen and Rias poured over ancient tomes and encoded documents recovered from the battle.
Among the fragments of corrupted scripture and forbidden lore, a name kept recurring—"The Seraphim Order."
A sect whispered about in myth and fear, said to be zealots wielding power rivaling even the devils and angels.
Kaizen's AI flickered with analysis: Potentially multiversal threat. Highly dangerous. Recommend immediate intelligence gathering.
Rias's eyes narrowed. "If the Seraphim Order has aligned with the Church, this war is about to escalate beyond anything we've faced."
---
🤝 A New Ally Arrives
A sudden knock interrupted their discussion.
The door creaked open, revealing a figure clad in white robes, her silver hair shimmering like starlight.
"I come with a message," she said, voice calm but carrying authority.
Kaizen and Rias exchanged glances. This was Seraphiel, a former angel rumored to have severed ties with Heaven to follow her own path.
"I have observed your battles," Seraphiel continued. "The Seraphim Order threatens all realms — mortal, devil, and angel alike. You will need allies beyond your walls."
Kaizen stepped forward, the weight of the moment settling on his shoulders. "We don't have time for old grudges. What do you propose?"
Seraphiel's gaze was steady. "A pact. To stand together against the coming storm."
---
⚡ Preparing for the Next Storm
Outside, the night deepened, but within the Gremory estate, a fragile new alliance began to form.
Kaizen felt the surge of multiversal energy coursing through him, tempered now with purpose beyond survival—leadership, unity, and a battle for the fate of all existence.
The crimson twilight had faded, but the fires of war had only just begun to burn brighter.
---
End of Chapter 15