Sunlight, pale and lost, pierced through the heavy shroud of ashen clouds, spilling across a land laid to ruin. From the earth, pillars of fire roared upward, while blackened craters gaped open like wounds torn into the body of the world—scars of countless cataclysmic blasts. Amid the flames and drifting ash lay the broken husks of warriors, their shattered bodies still clad in familiar armor: the fallen Riders. Around them, monstrous aberrations and twisted mutants shrieked in chaos, their cries merging into a dirge of the apocalypse.
Yet the battlefield had not fallen silent.
Through the thunder of explosions and the roar of hatred, two radiant forces—gold and black—clashed together, rising like monuments of destiny.
"Perish, Ohma Zi-O!!"
A golden longsword came crashing down, its weight immense enough to cleave the heavens themselves. Wielding it was a figure clad in gleaming gold armor—majestic yet unyielding. Upon his chest, the sigil of a golden insect blazed against a deep blue core. His helm burned with fierce crimson eyes, and from his brow jutted a radiant golden horn, sharp as a divine spear. He was Kamen Rider Blade (King Form)—the final champion of humanity.
Opposite him stood the one who caught that blade with but a single hand. His form, black and gold, loomed like an immortal monument, his armor carved with ominous dark engravings. His helmet bore the visage of a colossal clock, its twin hands forever marking the flow of time. Within its frame, dual crimson eyes blazed with cold, absolute disdain. He was none other than Ohma Zi-O—the Demon King supreme, ruler who crushed and consumed every flow of history.
In the sea of fire and ruin, the two figures faced one another.
God and Demon, colliding to decide the fate of the world.
"Hmph… you still refuse to give up? Very well… I'll see you off on your final journey."
Ohma Zi-O's voice was deep and cold, devoid of all humanity—like a verdict already sealed. As his words fell, thick torrents of black energy erupted from his body. With a mere flick of his hand, Blade was hurled away, his body grinding across the scorched earth, throwing up stone shards and embers.
Blade staggered, forcing his golden sword into the ground to anchor himself. Harsh, ragged breaths echoed amid the roar of flames. His eyes blazed with fury and grief. His body trembled, yet he stood tall, lifting the King Blade to point straight at Ohma Zi-O, his hoarse voice breaking into a roar:
"Tsk… Ohma Zi-O! You bastard—don't even dream of stealing our power!"
"Hmph."
The twin crimson eyes of Ohma Zi-O flared, his words slicing through the void like a blade of ice.
"Do you truly think you can defy destiny? Hand over your power now, and perhaps I will allow you and those you cherish to live… But if you resist? Then your fate will be no different from the others who have already fallen."
Kazuma's grip tightened on the hilt of his sword. He knew the abyss loomed before him. He also knew that surrender meant the world would be crushed under the heel of the Demon King. Resolve burned within his chest—he would strike, even if it meant his end. He surged forward when—
Thud!
A hand clapped firmly on his shoulder. Kazuma spun around, startled. Behind him, another Rider had appeared.
Armor pure white gleamed against the inferno, one gauntlet glowing with blue flames. A black cloak billowed violently in the scorching wind. His right hand clenched a short dagger, his helm sharp and angular, its brow engraved with a crimson trident gem. Twin golden compound eyes locked onto Kazuma, a silent assurance burning within them—words were no longer needed.
None other than—Kamen Rider Eternal.
"You're… Eternal? Didn't you—"
"Ayo~! Kazuma-senpai, it's me." Eternal flashed a confident thumbs-up.
"That voice… Kagami?" Blade froze.
"Yup! It's me. Looks like I showed up just in time, huh? Here—take this." Eternal smiled, produced a Rider Watch that swung on his palm, and pressed it into Kazuma's hand. It was a Ghost Rider Watch.
"Kagami… you—"
"Hey, I'm just borrowing some of Kaito-senpai's style." Kagami grinned and stepped forward to face Ohma Zi-O.
Kazuma, however, tightened his grip on Kagami's shoulder and tried to pull him back, eyes blazing, voice firm: "You should fall back. This fight… I'll carry it."
Kagami shoved Kazuma's arm off. Eternaledge flashed in his right hand; his left plucked a bone-white Gaia Memory and slammed it in. A cold mechanical voice announced:
[Zone!]
"Kazuma-senpai… hold the last line at the refugee camp. I'll buy time and fight Zi-O."
"Kagami! You're insane! Fall back now!" Kazuma shouted—but it was too late.
Kagami decisively slotted the Zone Memory into the Maximum Slot at his hip and activated.
[Zone! Maximum Drive!]
"UAAAAHHHH!!"
A roar split the air. His black cloak tore apart as blue energy detonated outward, carving the battlefield into a web of chasms. Twenty-six T2 Memories orbiting him snapped into the Max Jacket, Arm-Max, and Thigh-Max belts—unleashing world-shattering power.
BOOM!!
The shockwave hurled earth and stone into the sky, the ground cracking in spiderweb fractures. When the dust cleared, at the eye of that storm stood a single figure—
Eternal.
He had entered Strengthening Armament.
"Kagami! Get back here!!" Kazuma staggered through the aftershock, clawing at him, desperate to drag his junior from the crucible of death. He didn't want to see another young life thrown away.
Kazuma understood. No matter how mighty he, Tachibana, Tendou Souji, Kouta Kazuraba, or the others had been—before Ohma Zi-O they were dust. This battle was a hopeless stand. Yet at least they could buy humanity one last breath.
Kagami chuckled quietly and scratched his helm. His tone was calm but edged in steel: "Kazuma-senpai… you know me. I was never great like you. I was a Dai-Shocker experiment… an Unnamed Demon, stained with countless innocent lives."
He raised Eternaledge; blue light reflected in his golden eyes: "Now… I can at least atone. I'll use my life to stall him. And you—take that Rider Watch to the refugee camp. Maybe one day someone strong enough will use it… to end this tragedy."
"Don't spout nonsense! Get back here!!" Kazuma roared until his throat tore. But suddenly, a firm grip seized his shoulder and yanked him back.
Startled, Kazuma spun around—eyes blazing red as he shouted at the familiar figure:
"Tachibana! Let go of me! Stop that fool, now!!"
Tachibana's face was taut, strained with worry yet filled with resolve:
"What are you clinging to? Fall back to the refugee camp! Here… let Kagami decide."
Kazuma thrashed, heart shattering in his chest. Tachibana understood too—letting Kagami shoulder this burden was another tragedy. But the choice had already been carved in stone; regret no longer mattered.
In the sea of fire and smoke, Kagami charged straight at Ohma Zi-O. Eternaledge carved arcs of cold blue light, ripping open the air. But the Demon King merely tilted aside, stepping back with casual amusement, as though toying with prey. Then he gathered power, and struck.
BOOM!!
His fist crashed through Kagami's chestplate, blasting him away like a severed kite. His body smashed into a mountainside, crushing it into rubble and choking the world in dust.
"Hmph. Pathetic." Ohma Zi-O's contemptuous voice echoed, ice filling the heavens.
"Khff…" From the ruins, Kagami staggered back to his feet. His armor cracked, then knitted itself whole in an instant, body restored as though untouched. The golden eyes on his helm flared, reflecting the crimson inferno of doomsday.
"Oi! I'm an immortal bastard, Ohma Zi-O… and you—you damned tyrant—time for you to go down!!"
He crouched. The ground beneath erupted. In a flash, Kagami shot forward like a blue comet, Eternaledge rending through the sky.
Ohma Zi-O stood unshaken, twin crimson eyes gazing down with disdain. Black energy poured off his armor, devouring Eternal's light like a midnight tide.
"Arghh…!!" Blood streaked Kagami's lips, yet his gaze blazed fiercer. He tore the Eternal Memory free and slammed it into Eternaledge's Maximum Slot, pouring his very life into one final strike.
[Eternal! Maximum Drive!]
Azure radiance exploded, engulfing him, transfiguring his body into a living star. It shattered the net of black energy that bound him, his roar ripping open the chains of fate.
High above, Kagami caught his balance. From the heavens, he dove—a furious meteor. His right leg trailed a blazing torrent of azure fire—the Flame of Doomsday.
[Never Ending Hell!]
A Rider Kick—not just a finishing blow, but a funeral hymn to the world itself.
"Fall into the abyss of hell, Ohma Zi-O!!"
Ohma Zi-O smirked, his laughter slicing the void like knives. He slammed his Driver. The gears of destiny howled, and beneath him bloomed a golden-black clockwork sigil—a requiem of annihilation.
[Shuuen No Toki!]
[Ohma Zi-O Hissatsu-geki!]
"Brat… to be buried under this kick is your final honor!!"
Two Rider Kicks—one azure, one gold—collided. Space shattered. Time exploded. The world trembled beneath the judgment of two fated legs. All sound was snuffed out, leaving only silence—waiting for the end.
---
"Am I… dead?"
Kagami's voice echoed through the void. He opened his eyes—only fragments of white armor drifted aimlessly around him, swallowed by an endless darkness. No direction. No flow of time. He floated, like a soul torn from flesh.
He tried to move, but his limbs were illusions. The weight of existence was gone. Only raw consciousness remained, helpless, imprisoned. The sensation dragged him downward, coaxing him to surrender, to dissolve into the abyss.
And within the darkness, memories began to surface.
He was Saito Kagami, twenty one years old. A vocational college student. An ordinary nobody. And—an "isekai traveler."
That day, at the gas station, as he refueled his bike, a compact car reversed by mistake and struck the pump. Flames erupted. Before the attendants could act—BOOM! The station exploded. His body was consumed by fire… that death became the doorway to another world.
When he opened his eyes, his hometown was gone. At first, he thought it was just a parallel world: schools, jobs, people. But fate delights in mockery.
One day, on his way to work, the road lay empty. Suddenly, grotesque figures blocked his path, clapping like in some demonic ritual. A bouquet of jet-black flowers was thrown at his feet, like the garland of a condemned man.
"Congratulations! You've been chosen… to serve Dai-Shocker!"
"…Huh?"
Before he could react, they dragged him away. Chains. Laboratories. Electric fire. Surgical blades. His flesh carved open, blood drained, bones fused with cold steel. His mind warped, memories erased. Kagami was no longer human. He became a half-cyber abomination, a soulless tool of Dai-Shocker.
In those endless experiments, they discovered his ability to connect with the Gaia Library—the mysterious archive of all Earth's knowledge. From that day, when the Eternal Memory surfaced, Kagami was forced to bear a dreadful title: Unnamed Demon, the third wielder of Eternal.
He was sent to the battlefield, eyes lifeless, body a slaughtering machine. But fate mocked him again. In Fuuto City, he clashed with Kamen Rider W—Philip and Shotaro.
The battle shook the streets. Kagami collapsed. That fall awoke the sealed fragment of his humanity. Shotaro's voice, Philip's gaze—shattered Dai-Shocker's chains.
From that moment, Kagami ceased being a tool. He lived for himself. Yet the path he chose was atonement.
Too much blood stained his hands. Too many souls torn apart. To repay, he hunted monsters: Greed, Orphnoch, Fangire, Gurongi… each felled beneath his boots. An invisible verdict, and he himself the executioner.
But history spares no sinner peace. The storm of fate swept across the Rider worlds. One by one, Riders fell, their powers stolen by one man—Ohma Zi-O.
Kagami joined the war. Yet before the Demon King, all were dust. In a final gambit, he, Hibiki, and Kaixa stole Rider Watches, handing back a fragment of hope. Hibiki and Kaixa retreated to the refugee camp. Kagami, under the excuse of "saving more people," chose otherwise: he turned back, plunging into the frontline, to save Blade—trapped in a sea of blood.
That decision carried him to this moment. The death match against Ohma Zi-O. With no path left behind.
"Hahahaha… let's hope they can still protect humanity…"
Kagami let out a ragged laugh, dry and corroded like rusted iron dissolving into the void. He shut his eyes, face hollow, throat scorched—little more than a corpse that still knew how to breathe.
Time vanished. A day? A month? A year? No concept remained. Kagami drifted endlessly—formless, voiceless, colorless. A ghost abandoned on the fringe of the cosmos.
Then, within that eternal dark, a white light flared in the distance. It pulsed as though calling his name.
His armored arm trembled—then moved. Without thinking, he reached for it. The radiance tore through the void, forcing him to squeeze his eyes shut, shielding his face as his whole being was dragged out of the abyss.
When he opened his eyes again, he stood in a boundless expanse of pure white.
"Welcome… traveler from another world."
A clear feminine voice rang out. Kagami flinched, instantly raising the Eternaledge into guard. Yet before him floated only a sphere of azure light, silently observing.
Lowering his weapon with caution, Kagami growled:
"…Where is this? And what the hell are you?"
The voice replied, cold and without emotion:
"I am one of the Two Counter Force—Alaya. The embodiment of humanity's collective will."
"I see…" Kagami scratched at the side of his helmet. "So you're the one who dragged me here?"
"Yes. Within the digital void, I sensed a will struggling against despair. I followed it… and found you."
"Digital void, huh? That sounds… abstract."
"I must confirm: are you a threat to humanity? And by what means did you enter that space?"
Kagami shrugged. "How should I know? The last thing I remember was throwing myself at Ohma Zi-O. And if I really were a threat, I doubt the senior Riders would've let me walk around in one piece."
"Riders? Ohma Zi-O?"
"Guess you've never heard of tokusatsu, huh." Kagami smirked faintly.
The sphere hovered in silence for a beat, then spoke again:
"Very well. If you are not a danger… then, traveler, will you stand on humanity's side?"
"Do you even need to ask? If I wasn't on their side, I wouldn't have thrown my life away standing against the Demon King in Kazuma-senpai's place."
"…Calculation complete. Then I permit you to set foot in our world."
"Wait, hold on! What the hell is your wor—"
Before he could finish, Kagami's body dissolved into nothingness. In the next instant, a vision opened before his eyes.
Neon lights blazed. Music thundered across a crowded plaza. Car horns blared in chorus with the clamor of rushing footsteps. A metropolis, radiant and alive.
Kagami pulled the Eternal Memory from the Lost Driver, cancelling his transformation. His ordinary human form stood adrift in the tide of strangers. He froze on the sidewalk, his gaze dulling.
"…You've got to be kidding me. I transmigrated again?"