Both Decade and Geats slammed into each other once again, their blades locked together as sparks erupted between them in a bright spray of white and gold light. The sheer force of the collision sent both Riders hurtling sideways, crashing through the outer wall of a nearby office building and disappearing into it in a burst of concrete and broken glass.
The inside of the building did not last long. Floor after floor was torn open as the two of them smashed through it like cannonballs, each impact shaking the entire structure hard enough to rattle desks, crack monitors, and send papers, chairs, and shards of glass flying through the air.
A few unlucky objects were simply pulverized in the chaos, while others were thrown out of the way as the two Riders kept moving through the building at full speed, never once slowing down. By the time they reached the other side, the office building was already leaning dangerously under its own damage, unable to keep itself standing any longer.
With a deep, groaning sound, the entire structure tipped to one side and collapsed onto the street below.
The impact rolled out across several blocks like a heavy wave, swallowing abandoned cars, shattering what was left of nearby windows, and tearing fresh cracks into the pavement. Dust and rubble surged outward, filling the air with a dense gray cloud that made the entire area look like it had been buried under a sudden collapse.
Yet before the destruction could truly settle, a faint white light began spreading through the ruined city.
The fallen building trembled.
Chunks of broken concrete lifted back into place one after another. Twisted steel beams straightened themselves. Shattered glass flew back into broken windows and reassembled into whole panes. Loose rubble rose from the streets and drifted upward as if time itself had started running backward, undoing the damage piece by piece.
Within only a few seconds, the entire building had returned to its original shape, standing exactly as it had before the battle, as though it had never fallen in the first place.
Only the lingering dust and the force of the shockwaves remained to prove that it had happened at all.
Then, almost at the same time, both Riders burst out from opposite sides of the restored building and charged toward each other again.
Neither of them said anything.
They did not need to.
Their swords met the instant they closed the distance, and the impact twisted the air around them before another violent shockwave exploded outward. Windows shattered across nearby buildings. Streetlights bent under the pressure. Several parked vehicles were flipped over and sent tumbling down the road, crashing into one another as the force rolled through the block. Even the road itself could not withstand the collision, and cracks spread outward from where they stood like a spiderweb breaking across the asphalt.
Decade twisted his wrist and knocked Geats's blade away before throwing a kick toward his chest, but Geats caught the kick with one hand. The pavement beneath his feet immediately fractured into a web of cracks from the force, yet he did not move even an inch. He simply stared back at Decade with that calm, unreadable composure of his, as if the damage around them was just background noise.
The next instant, Geats swung his sword horizontally.
A crescent of white energy tore across the city, cutting through the air with enough force to slice through anything in its path. Decade simply walked forward and let the energy slash crash into him head-on, but it could not break through his invincibility. The attack dispersed against his body and burst apart behind him, failing to slow him down in the slightest.
Decade responded by swinging his own blade toward Geats once.
Geats reacted instantly and brought his weapon up to intercept. The two blades collided again, and this time the impact produced another explosion powerful enough to split the road beneath them. The ground sank several meters, the surrounding pavement crumbling inward from the pressure, before Geats's reality manipulation restored it once more, snapping the ruined street back into place as if it had never broken.
Neither Rider gave the city time to recover for long.
The instant the terrain returned to normal, the two of them disappeared again.
To anyone watching from a distance, they had become little more than streaks of gold and white flashing across Nagoya in rapid bursts, each movement too fast to follow cleanly with the naked eye. Every few moments another building would explode. Another street would collapse. Another section of the city would be swallowed by destruction before Geats casually restored it again, as though he were simply undoing a mistake with the press of a button.
It became a bizarre cycle. Destroy. Restore. Destroy. Restore.
The city was being torn apart and put back together in the same breath, and neither side seemed capable of forcing the other to stop.
Hyper Muteki's invincibility prevented Geats from landing a decisive blow. At the same time, Geats's god-like authority prevented Decade from building enough momentum to overwhelm him. Every attack was blocked, erased, redirected, or rendered meaningless before it could finish.
Seeing that his attacks were not working, Geats shifted his approach and tried to drag Decade into a parallel world of the one they were currently standing in.
The moment the dimensional shift took hold, Decade reacted to it almost immediately. His transformation destabilized, and he was forced back into his base form as the new world recognized him and began assigning him a different identity. The sudden change made him hesitate for only a fraction of a second.
"What?"
He murmured under his breath, clearly catching the shift just a little too late. Geats took that opening without wasting a single second, swinging his sword toward him before Decade could fully adjust. Decade raised his hand to block it, but the force behind the strike still sent him skidding backward across the ground before he rolled once and pushed himself back up.
He straightened, then looked toward the Creator God standing before him.
"So this is your weakness..." Geats murmured, and there was a faint edge of amusement in his voice.
The dimensional shift was reacting to Tsutsumi Ryoko's special existence. Every world he entered tried to recognize him and force an identity onto him, and in this case, that reaction stripped away the stability of Hyper Muteki and pushed him back to the point before he had fully settled into the transformation. It did not completely erase the power itself, but it was enough to interrupt it and force him to adapt again.
Geats pressed the advantage immediately.
He closed the distance and attacked relentlessly, not giving Decade any space to recover. Decade raised his arms to intercept, but Geats was already moving faster than he could fully reset his footing. His sword came down with enough force to cut both of Decade's arms clean off.
The severed limbs fell, but Decade did not even look bothered.
Blood burst outward from the wounds at once, and with Blood Manipulation working together with Reverse Cursed Technique, he reattached both arms instantly before the damage could settle. The process happened so quickly that it barely interrupted his posture at all. In the same motion, he clapped both hands together and condensed blood between his palms before firing it forward in a single concentrated shot.
"Piercing Blood!"
The attack shot straight toward Geats with enough force to rip through the air, but Geats did not even look like he needed to hurry. He lifted one hand calmly, and an invisible barrier formed in front of him, stopping the attack cold before it could reach him. The blood spread out across the barrier for a moment, then was pushed aside and sent veering away from its target.
Decade clicked his tongue and reached for another card.
Final Kamen Ride: Ex-Aid! Muteki Gamer!
Sparkling golden light erupted around him once more as he transformed back into Muteki Gamer. For a brief moment, the invincibility returned to his body, and the familiar radiant clothes of Hyper Muteki settled over him again.
But Geats responded just as quickly.
Before Decade could make proper use of it, Geats forced another dimensional shift.
The world reacted once more, and Decade was dragged back into his base form again as his identity was overwritten by the new parallel world they had been pushed into. The transformation was interrupted a second time, leaving him forced to reset yet again while Geats continued pressing forward without pause.
Continuing to be pressured and knocked around like a ragdoll by the Creator God, Decade reached for the Time Vent Ride Card, clearly intending to use it to turn the battle around. But Geats seemed to immediately sense the overwhelming time-manipulation power contained within it, and the moment Decade tried to bring it out, the Creator God swung his blade down without hesitation.
The slash landed before Decade could fully react.
A deep cut opened across his face and hand at the same time, and the blade cleanly split the card in half before it could be used. Blood spilled out from the wound, but Blood Manipulation and Reverse Cursed Technique kicked in immediately, closing the injury almost as fast as it had appeared. The damage was healed in an instant, and the moment his other fist tightened, black and crimson lightning burst around it.
He drove the punch straight into Geats's chest.
"Black Flash!"
The impact finally made Geats react, if only slightly, but it was nowhere near enough to stop him. With almost no delay at all, Geats answered by swinging his blade down on Decade again and sending him flying back once more. Decade skidded across the ground before forcing himself to stop, his breathing heavier now as he looked up at the Creator God walking toward him with complete confidence, as if he had already decided the outcome of the fight.
Decade clicked his tongue and opened an Aurora Curtain, intending to escape and reset the situation, but Geats raised his hand at the same time. The world around them shifted again, forcing the dimension to change before Decade could slip away. The Aurora Curtain was left behind in the previous world, and Geats simply moved both of them into yet another parallel dimension before Decade could use it.
"Trying to leave? That won't be so simple," Geats said with a smug tone, watching the world around them continue to switch from one parallel world to another in rapid succession. He was doing it deliberately, using each shift to make sure Decade never had a stable exit point long enough to escape through the Aurora Curtain.
Then Geats pressed the lever on his driver.
Nine bright blue flames burst out from it all at once.
BOOST IX VICTORY!
Geats leaped forward, blue energy gathering around his right foot as he descended in a straight line toward Decade. The force behind the attack was unmistakable. It was a Rider Kick meant to end the fight here and now, aimed directly at the already injured Destroyer before he could properly recover.
A figure suddenly rushed forward and stepped in between them, her arms spread wide as Ryoshu threw herself in front of the finisher meant for her brother.
The impact hit with enough force to send her flying backward, and Decade was dragged along with her as the two of them crashed through several ancient buildings before finally coming to a stop in a crater together. Dust and debris rolled around them for a moment, settling slowly over the broken ground as the aftermath of the attack echoed through the ruined area.
His body ached from the impact, but he ignored the pain completely. All of his attention had already shifted to the person lying in his arms.
"...Ryoshu?" His voice came out unsteady, thinner than he expected.
The woman who had been standing in front of him only moments ago now rested heavily against his chest, her body frighteningly limp. Blood stained the front of her clothes and kept spreading little by little, soaking deeper into the fabric with every passing second. Even without checking her wounds properly, he could tell what had happened. Geats IX's finisher had torn through her body far too severely for this to be something he could simply patch up and pretend nothing happened.
She was not going to survive.
"...Ryoshu...?" His breathing had already started to turn uneven. "...What are you doing...?"
His hands tightened around her shoulders without him even meaning to. It was the kind of instinctive grip a person made when they refused to accept what was happening, as if holding on a little tighter would somehow stop the other person from slipping away. As if strength alone could force reality to change.
"You..." His voice cracked in the middle of the word. "...Why?"
Ryoshu slowly opened one eye.
When she saw the expression on her little brother's face, a faint smile appeared on her lips, small and tired but still unmistakably hers.
"...Sorry."
Her voice was quieter than usual. Quieter than he had ever heard it before.
"I was... pretty useless... when we lived together..." She gave a weak, almost self-deprecating laugh, though it barely had enough strength behind it to count as one. "...Your big sister..."
She paused to take another shaky breath.
"...has always done things... instinctively."
Ryoko stared at her for a moment before the word repeated itself quietly in his mind.
"Instinctively, huh...?"
It sounded like such a simple thing, but coming from her in a moment like this, it carried far more weight than it should have. Ryoshu had never been the kind of person to explain herself in roundabout ways, and even now she was not really doing that. She was just speaking plainly, in the same way she always did, only now the words felt heavier because he could hear exactly how much effort it was taking for her to say them.
Ryoshu took another shallow breath and kept going, clearly wanting to make sure he understood her before she could no longer speak properly.
Her fingers rose with visible effort and brushed lightly against his cheek.
"They..." She had to force the next words out, one at a time, as if pulling them through pain. "...might throw us... into different parallel worlds..."
Her breathing became weaker with every sentence.
"Our lives..."
"...our memories..."
"...our circumstances..."
"...they're all... different..."
Even now, with her body breaking down and the world itself feeling distant around them, a faint smile remained on her face.
"But..."
She looked directly into his eyes.
"...our bond... never changes."
"I..." Her lips trembled slightly before she pushed on. "...loved you... in every world."
The words hit him harder than he expected.
Not because they were dramatic.
Not because they were some grand confession meant to leave an impression.
It was because she said them so simply, so honestly, that he could not ignore them. Even now, even in this condition, even with her life slipping away from her, she was still thinking about him in the same way she always had. Not as a stranger. Not as some version of him she had to get used to. Not as a replacement for someone else.
As her little brother.
Across every world, across every version of their lives, that part had never changed.
Ryoshu gave him one more faint smile, warmer this time despite how weak she looked.
"...I'm sorry..."
The words were barely more than a whisper now.
"...for leaving you alone."
Her eyelids had already started to grow heavier, and each breath looked like it cost her more than the last.
"You... were there... when I needed someone the most."
She let out another quiet breath, the kind that seemed to carry the last bit of strength she had left in it.
"...That... is more than enough for me."
Ryoko lowered his head slightly, his fingers tightening around her hand as if he still could not bring himself to let go.
"...Is that so..."
He could feel her hand growing colder in his grasp.
He kept pouring Reverse Cursed Energy into her body again and again, desperately trying to force her wounds to close, to pull her back from the edge, to make reality obey him for once. But the damage was far beyond what his current abilities could restore. No matter how much reverse-cursed energy he pushed into her, it was not enough to bring back what Geats IX had already taken away.
For the first time in a long while, he truly felt powerless.
Not because he had run out of strength.
But because there was nothing left for that strength to fix.
Ryoshu's eyelids grew heavier still.
Even so, she smiled.
It was not a bitter smile.
Not a regretful one, either.
Just a warm, gentle, satisfied smile, the kind that made it feel as though she had already accepted everything and was simply choosing to leave this world the way she wanted to.
"...Thank you, Ryoko."
Her voice was almost gone by then.
"...for being... my little brother."
Ryoko stared at her.
His purple eyes, which usually carried such calm indifference, slowly lost that steadiness. The emotions he had spent so long burying beneath indifference finally rose to the surface all at once, and for a moment he could not stop them from reaching his face.
His vision blurred.
A single tear slipped from the corner of his eye and ran quietly down his cheek.
Then, slowly, he lowered his forehead against hers.
"...Thank you..." His voice shook. "...Big Sister."