When Bunny Learned to Drive a Tank and Returned to Shout "666" for the Emperor

Note: The latter half of this chapter is a treat for Kamen Rider fans; we apologize for any inconvenience this may cause to non-Knight Rider readers. Also, the author's original Knight Combination differ slightly from the official ones because the official pairings are incomplete. Additionally, there are some settings I added myself, so please be aware of the differences.

Let's give a shout-out to Our Emperor!

In the dilapidated city, a golden-glowing warrior strolled leisurely through the monsters' encirclement, his sword dragging across the ground, leaving a long trail of sparks.

The destiny of a decisive battle continues again and again.

I still retain that undying ambition.

Traversing through several lifetimes of light and shadow

Having experienced victory or defeat on the battlefield

Holding onto the savior complex to this day

The Emperor's Hero's exclusive background music – "The Emperor Returns"

The overcast sky obscured his brilliance, and he slightly raised his red mask to see the enemy before him.

A swarm of blood-red bats circled around the alien Kiva as it swiftly attacked the Emperor, intending to unleash Kiva's ultimate attack—Dark Moon Strike.

But how could a king possibly take the attacks of petty villains seriously?

"Emperor—"

The five elemental crystals on his belt spun rapidly, but fortunately, he didn't notice. The beast-shaped warrior pattern that he had added his own touches to had now become the symbol of the First Generation five Kai.

(Hey, who secretly gave him the Emperor's power? Confess!)

"Piercing Wind Strike".

The hilt of the Aurora Sword opened, and the Wood Wind Eagle Crystal popped out from the belt. After combining with the Aurora Sword, a pair of light wings spread on the back, and the king soared high, looking down at these ignorant fools who dared to offend his majesty.

Although Sachi himself cannot compare to the Emperor, with the power of both the Knight World and the Honkai World at this moment, he is the true Emperor Knight!

PS: When the World Power arrives is random.

Unseal the latent power with courage

Waiting for the next myth to descend

I've traveled the world, from far to near, and tasted both the warmth and the coldness of human relationships.

The dormant memories are about to awaken.

The Otherworld Faiz, driving a mutated Crimson Drill, attacked from behind. Without even glancing at him, Faiz clenched his left fist tightly—

Otherworld Faiz abruptly stopped moving, then quickly changed direction and crashed into Otherworld W lying on the ground.

One of the Emperor's abilities is telekinesis.

The light wings broke into countless light spikes that shot towards the alien Kiva, killing it with the first wave of attacks. Fortunately, it did not stop there. It injected the five elements energy into its legs and launched a flying kick forward, instantly blasting the Megamorph alien Kuuga behind the alien Kiva.

"Boring. You guys, with only your basic forms, don't interest me at all," said Happiness, who was suffering from chuunibyou (middle school syndrome).

The alien beast spun rapidly around him, and Xing frowned slightly, clasping his hands together in front of his waist.

"My eyes are blurred from looking at it; I'm in meditation."

The Emperor's Wrath

PS: Fortunately, this is a simulation using magic. Unlike the original's direct time stop, this one freezes space.

The movements of the surrounding Otherworld Rider all stopped. Fortunately, he walked up to the alien rider, reached out and gently flicked its chest, and then released the meditation seal.

Boom!!!

The moment it resumed movement, the alien rider's body flew out like a cannonball and disappeared into the sky in the blink of an eye.

"Hmm?" As if sensing something, he turned his head and noticed that Another Den-O had abducted a little girl from who-knows-where.

"If you don't want this child to get hurt, put down your sword!" Another Den-O defiantly slashed a bloody gash across the little girl's neck.

"You're courting death." Xing walked towards it, and the surrounding Otherworld Rider wanted to attack. Another Electric King, seeing that he was not cooperating, planned to kill the hostage, but they all found themselves unable to move.

One of the Emperor's abilities—the Emperor's Magnetic Field.

The Aurora Sword split open, and the blade hidden in the scabbard popped out. Fortunately, the little girl who was crying incessantly was rescued from the immobile Another Den-O. The hand covered in metal armor gently stroked her head. "Don't be afraid, I'm here."

Emperor's Benevolence

Fortunately, he covered her eyes, raised his sword, and the Otherworldly Electric King exploded in a dazzling display of fireworks.

The golden figure vanished in an instant, only to return to its original spot in the blink of an eye. After delivering the little girl to safety, it returned to the battlefield to continue its battle with the remaining Otherworld Rider.

No, this cannot be called a battle, it should be called -

Torture and murder.

The resurrected alien dragon riders flew out of the mirror riding the mutated and modified Ryuki Crimson. The demonic dragon opened its bloody maw and spewed a mouthful of demonic flame at the emperor.

"A dragon?" Xing dispersed the flames with one hand, as if he had become interested. "I have one too."

"Put on your armor and step onto the battlefield; forged in fire, you'll grow stronger with each challenge."

The sun's rays reign supreme; your gaze gives me strength.

Donning armor and returning to the battlefield, my glory is on your shore.

Memories of the city walls, chapters of bygone years unveil the long-forgotten face of a king.

The long-unseen Jilin War Rider charged out, smashing through the demonic dragon before seemingly transforming into an imperial steed and stopping steadily beside the emperor. A beam of light flew out, and the imperial steed quickly passed through it. A majestic mechanical dragon emerged from it, its blade-like tail springing out and circling around the emperor like the most loyal guard.

Emperor of Light Battle Dragon!

That wasn't all. An even more powerful aura erupted from the Emperor, a shield-like breastplate appeared, and the armor on his arms became even more magnificent.

Ultimate Emperor Armor!

The emperor rides a war dragon and begins a new round of slaughter against the resurrected enemies.

The clash of light and shadow resulted in the defeat of the alien dragon rider and his magical beast, who were cut down by the king in a single move.

Another Blade, wielding a greatsword, attacks; Another Fourze, wielding a rocket and a drill, descends from the sky; Another Ex-Aid, riding on Yugi blocks, rushes down from the ground, his sword pointed at the Emperor.

"Emperor—"

"Raging Waterfall!"

With a single move, all things are annihilated.

Noticing the constant resurrection and rebirth of the Otherworld Rider, Xing pondered for a moment, then summoned the Water Mark and lightly touched the tip of the Aurora Sword.

"The Hiddenness of Water".

Countless ice crystals fell from the sky, freezing all eighteen Otherworld Rider at absolute zero. The alien Ghost escaped thanks to its ghostly nature, which ignores the laws of physics, and was thus granted the Emperor's Light and Shadow Scroll for its dimensional reduction seal.

I am a phoenix reborn from the ashes, I am my own emperor.

I emerged from the darkness, reborn as a prairie fire, and became the dawn.

My scars are my medals, and you are my safe haven.

Waiting for the white doves to fly over the battlefield

You sing for love and hate at the ends of the earth.

A gray dimensional curtain appeared in the ruins, and the magenta knight, who had been forced back to his basic form, staggered out. Pandir in his Otherworld Oma form followed closely behind, teleporting in front of Decade and throwing a punch.

After smashing through several buildings, Kamen Rider Decade, whose transformation had been undone, quickly picked up his hat and put it back on. He was going to go back and ask Sougo for more compensation for emotional distress; he had really lost out this time!

"Any last words, you foolish Kamen Rider?" Pandir, feeling he had everything under control, slowly walked up to him and looked down at the disheveled Wang Xiaoming.

"Next time, I'm never playing with them again." Tsukasa Kadoya complained helplessly. Can't you just leave the newbies alone when you're training them?

Pandir was puzzled, but he was still prepared to kill him, but at that moment, a dragon's roar resounded through the sky.

!!

Otherworld Oma swiftly sidestepped and unleashed a punch. The kings of two Branch World clashed here, their golden fists colliding with their dark red fists, the resulting shockwave nearly obliterating everything nearby—except for Tsukasa Kadoya was holding popcorn.

Wait a minute, where did you get the popcorn from?

"You actually dare to come back?" Pandir's face was gloomy, and powerful spacetime energy erupted from his body, intending to kill the unawakened Native Order Emissary in front of him.

"It seems my feeling was right. I am now strong enough to fight you." Even he himself could hardly believe that he was now on par with the strongest fighter in the Knight World.

After their fistfight failed, the two quickly distanced themselves. Five beams of light appeared in front of the Emperor, Otherworld Oma shone with a bright red light. Its terrifying aura excited the spectators.

After all, it's usually very difficult for them to persuade that king from the Armor Hero Branch World to come and play...

Five Saints' Ultimate Kill - Emperor's Demon-Slaying Annihilation Slash!

Fortunately, the War Dragon was summoned, and the Aurora Sword was inserted into the shield to form the Emperor's Halberd. The armor, dragon, shield, and sword were combined into one and charged towards Pandir.

Finality Moment: Ohma Zi-O's Ultimate Attack!

Pandir used all his strength, choosing not to use the Kamen Rider's signature Rider Kick, but instead opting for the Rider Slash, and the mutated Zi-O Decade Form Greatsword appeared in his hand.

The radiant golden king of light clashed with the imposter king emitting red light. In that instant, the impact of the collision of the two powerful forces could be felt in both worlds.

The Sento in the Honkai World stopped what he was doing. By the time he realized what was happening, the Genius Bottle and the Danger Trigger were already on his belt.

In the Knight World, Eiji and Ryuga, Ryuga happened to bump into him, looked at each other in bewilderment, not knowing what had happened.

"Ouch!" Ryuga was hit by an unknown object, snapping him out of the control state of Feather Crossing Dust. He angrily picked up the thing that had hit him on the head, and the familiar Build face came into view.

A faint ripple emanated from the Knight's watch face, instantly bringing the two people beside him back to their senses.

"What is this?!"

"I can sense Miss K's presence!"

—A genius will return driving a tank—

On the front lines, Tsukasa Kadoya threw away his popcorn and caught the white-haired girl flying out of the smoke with lightning speed. Sachi, who was forced back into idol form, looked at the Emperor Belt in her hand, which had broken down due to overload, with a sense of frustration. "Miss Jilin, can you please not crash at this time?"

Jilin: "What are you complaining about that I've managed to hold out for so long? Are those battles even my level? Please, don't accidentally break me, okay?"

"Are you alright?" The most kind-hearted knight gave her a bright smile.

Xing raised her head, her expression immediately becoming quite interesting. "Um, who... are you?"

Tsukasa Kadoya: "..."

That doesn't make sense. Didn't You Hui say she was a knight fan? How could she not even recognize him?

The girl scratched her head in annoyance. "It's mainly because of your hairstyle. Even if I know someone well, I'd have a hard time recognizing you."

Following her gaze, Kamen Rider Decade looked up and subconsciously touched his head, only to find that his Shotaro-style hat had been blown away by the blast wave, and his half-finished hairstyle was now exposed...

"Sougo! I'm not done with you yet!" Tsukasa Kadoya shouted angrily at the sky. Sougo, who was watching the live stream, touched his aching body, glanced at the Decade watch in his hand, and awkwardly summoned the Dimensional Screen, stuffing something into it.

Pandir staggered out of the smoke, still maintaining his Otherworld Oma, though he looked a little unwell.

"Damn it, but that attack just now must have used up all the World Power's bonus in a short time. She's no match for me now." Just as Pandir thought this, his gaze fell on the frantic Tsukasa Kadoya next to Sachi.

Damn, with this guy around, it's not easy to make a move. I just fought this overpowered Decade Knight, and now I'm fighting a high-quality knock-off of the Emperor Knight. I need to go back and rest for a while.

Let's also take back the power we released earlier; let's slow down the progress of the Corruption Knight World for now...

Pandir quickly teleported away, summoning the army of Otherworld Rider that had been sealed away earlier before leaving, so that they could slow down the two of them.

Seeing Otherworld Fourze's infuriating face again, Sachi was furious. But looking at the smoking Emperor Belt in her hand, she glanced at the armor bracelet on her wrist and was hesitating whether to make do with it when a few Red Feathers fell on her head.

"Huh, what's this?"

OOO Eternal Bird System Combination Form slowly descended from the sky, turned back and gave her a deep look, and Eiji, hidden under the mask, revealed a smile.

Although you've changed, I can still recognize you.

Ankh: "Didn't I recognize you? You idiot."

Brilliant fiery wings bloomed behind the rider as OOO charged into the enemy ranks and clashed with the Otherworld Rider. Tsukasa Kadoya dutifully pulled out OOO's piloting card from his belt, but was stopped by Sachi just as he was about to transform.

"What do you want?!"

"Don't worry, the pain is only temporary."

"Then tell me, how did you feel when Haidong transformed you?"

"... Could you please not mention this?"

While the two were fighting, Ryuga and the others found this place using the indicators on the Build Watch. "Hey! Sento sent you this! He even left a message on it: if there's no energy response from you, it will send it to me first. Get ready!"

The girl caught the knight watch that Ryuga tossed to her. The moment she held the red and blue watch in her hand, a warm current flowed through her body. She took out the Rabbit Tank Double Bottle, and the red and blue light illuminated her surprised face.

When I turned the watch cover and Build's complete portrait appeared on the surface, I pressed the button on the watch face.

Build!

"Well then, please allow me to say it this way: Sento- senpai, Ryuga -senpai, Kaito- senpai, Gento- senpai."

As she took out the Build Driver, her gaze swept over everyone present. When it landed on Tsukasa Kadoya, he coughed lightly, took out a box from the dimensional screen, and handed it to her. "Sougo asked me to give this to you. It should come in handy."

"Huh, full bottles? Wait, what are these?!" Sachi looked at the full bottles in the box with great surprise.

"Hey, there seems to be something stuck inside the box lid?" Tsukasa Kadoya curiously peeled it off, and upon closer inspection, his eyes widened in surprise.

On the other side, due to the presence of the Another OOO, Eiji was forced to suffer a setback and was pushed back to the girl's side. He felt extremely guilty, "I'm sorry, Miss K, I don't think I was of any use."

"No, Mr. Eiji." Sachi bent down and extended her hand to him. "The fact that you remember me is the best gift you could give me."

"Because it means that the bond we temporarily formed during that encounter still exists."

"Rabbit! Tank!"

The two bottles from the Rabbit Tank's belt emitted a brilliant light, and the three of them Ryuga were temporarily unable to transform, cheered excitedly from behind:

"Go! Give that imposter a good beating! Don't embarrass Sento!"

"Go for it, little sister! Remember to sing us a song after the battle!"

"What... should I say? Good luck!"

While Eiji was considering his lines, Tsukasa Kadoya pulled an ice pop out of the dimensional screen and handed it to him. Before Eiji could react, his left hand acted first and swallowed it whole.

Two distinct types of Honkai Energy triggered a series of reactions within the driver. After identification, the letters "R/T" in red and blue appeared on the driver's surface, and two sound effects rang out almost simultaneously:

Best Match!

Rider Match!

He paused for a moment, then smiled with relief, dodging the attacking Another Build, and brushed his middle and index fingers together over the fox ears that had suddenly appeared on his head.

"Alright, let's begin the experiment!"

Are you ready?

Fortunately, her lips trembled slightly as she uttered the incantation that summoned the knight:

"Transform!"

"Steel Moon Salt! Rabbit Tank! YEAH!"

Under the excited gaze of Ryuga and the others, the unfamiliar knight reappeared. The real one versus the counterfeit, and it was clear who was superior.

Tilting his head to dodge the attack from the Another Build, he managed to take out the Drill Crusher and slash it hard in the abdomen. As he was knocking it back, he suddenly exerted force with his left foot, and with the help of his superior jumping ability, he flew up and punched the Another Build in the chin.

Ignoring the attacks from the other Otherworld Rider, he quickly spun the lever to unleash his ultimate move. The white and black parabolas collided in mid-air, and the real Build defeated its own copy without any suspense. The pitch-black Another Rider dial fell from the sky, shattered, and never showed any sign of being restored.

As Another Build was completely defeated, the blank full bottles on Ryuga and the other two also regained their color.

"Taka! Medal! Rider Match!"

"Go to hell!"

Thanks to the special full bottle sent by Sougo, I was able to temporarily assemble all the Heisei Knight Combination.

A red, yellow, and green light wheel flashed, and Sachi, transformed into the OOO basic eagle-tiger-locust form, crushed the Another OOO with overwhelming force, making Eiji behind her shout with satisfaction.

Ankh's condition returned to normal, Eiji was about to go up and help when Tsukasa Kadoya stopped him, saying, "Let her play a little longer. Right now, she probably doesn't want anyone to disturb her battle."

Magic! Diamond! Rider Match!

"Alright, it's performance time!"

A red magic circle passed through the knight's body, and Wizard, clad in shimmering magical armor, gracefully emerged from it. Facing the oncoming counterfeit, she casually summoned a magic circle, then calmly reached her hand into it. An enlarged finger flew out from the other side of the circle, smashing the Otherworld W to pieces.

"Orange! Lock! Rider Match!"

"Next, it's my stage!"

A large head resembling an orange fell from the sky, landing on Sachi's head and forming the armor of Gaim. Sachi drew the Great Orange Maru and Musou Saber from his waist, glanced at the alien Gaim over there, and decisively threw the Great Orange Maru away.

A certain god, who had been dragged over by Sougo to watch the live stream, cried out in anguish, "Stop! That's not how you use the Great Orange Maru!"

You Hui, standing next to him, looked at him with disdain. "Tch, don't you even think about who started this trend?"

After a brutal mowing down of enemies, the alien armored warrior fell unwillingly behind the knight, and a dazzling firework rose into the sky.

'Friendship! Rocket! Rider Match!'

"The universe has arrived!"

Sachi, now transformed into Rocket Head being, raised her hands and shouted to the sky. Then, she lowered her head in shame, and drills and rockets appeared on her body. In a fit of pique, she kicked the alien Fourze into space.

"Ghost! Parka! Rider Match!"

"Burn your life!"

A hooded jacket with orange accents and black as the main color flew out of the driver, spun a few times in the air, and then attached itself to the rider, forming the Ghost basic form. After removing the hood, he formed hand seals, and after a complex eye pattern formed behind him, he kicked another Ghost that was also in full power.

Without any hindrance, the knight passed right through the counterfeit's body and landed on the ground.

'Doctor! Yugi! Rider Match!'

"I will change the fate of my patients!"

The magenta knight Ex-Aid, with his flowing hair, makes a dazzling appearance, wielding a small hammer and beating the otherworldly Ex-Aid senseless before finally finishing him off with a finishing move.

"Imagine! Ressya! Rider Match!"

"I'm here!"

Fortunately, he uncontrollably struck Momotaros' signature entrance pose and uttered that classic line, making Kamen Rider Decade, who was eating popcorn, watching the show, and taking photos, laugh like crazy.

After wielding the little red sword and hacking away at Another Den-O to death, Yuki looked at the Full Bottle that had granted him power with a sense of frustration. "This is the Imagin Full Bottle, not the Momotaros Full Bottle. Why did it shake out a peach?"

"Inspector! USB! Rider Match!"

"Come and count your sins."

A gust of wind swept by, and the green and black-clad knight W pointed at the person, the Otherworld W replying in a low voice, "Can you still count the numbers now?"

"You'd better count them even if you can't!" Xing defeated him with a merciless, body-splitting kick.

Unicorn Beetle! Watch! Rider Match!

"Grandma said that I am the innate Dao, the one who governs everything."

In a world where time is accelerated, two red figures engage in a fierce battle. Just as the alien Kabuto was about to unleash his Rider Kick, Yuki, who was much faster than him, quickly turned around and easily defeated him with a spinning kick. Yuki then raised his right hand and pointed to the sky, exuding an air of superiority.

Same (shark)! Smapho (smartphone)! Rider Match!

"I may not have my own dreams, but I can protect them."

Two similar Crimson Drill clashed fiercely in mid-air. Just as the Otherworld Faiz was about to exert its strength, dozens of Crimson Drill pierced its body in an instant. It roared in resentment and then exploded.

Amidst the fireworks, Faiz, who had temporarily switched to his accelerated form, calmly landed and crouched down. After standing up, he shook his hands.

"Bat! Lock! Rider Match!"

"Kivat, go!"

The sky suddenly darkened, and a moon adorned with a bat pattern hung in the air. Kiva's chains came off, his red bat wings unfurled, and the true Dark Moon Strike was unleashed.

The alien Kiva was knocked down in one blow and sent flying into a distant building, the cracks from the impact forming the Kiva symbol.

"Dragon! Mirror! Rider Match!"

"I will end the knights' battle!"

A giant red dragon flew out of the mirror. Amidst the shattered shards, the dragon rider slowly emerged, his Dragon Saber clashing with the weapon of the alien dragon rider. After the Otherworld Rider was defeated, flames erupted from the dragon head on its left hand. Before it could even attack, a majestic dragon head weapon struck it.

"The final moment has arrived!"

The Ryuki Crimson circled around Sachi, the swirling air lifting them into the air. A final burst of flame propelled the knight's kick, and the dragon rider's right foot slammed into the alien dragon rider's chest, ending the battle without a doubt.

'Light! Evolution! Rider Match!'

"No matter who it is, no one can take away someone else's future!"

In the dazzling light, Kamen Rider Agito stepped out, and the shining symbol appeared at his feet before being injected into his body.

The knight's two horns unfolded into six horns, and he calmed himself down, using the knight's kick once again to end the battle.

"Ghost! Drum! Rider Match!"

"Hey, kid!"

A ghostly flame ignites, and Kamen Rider Hibiki, wielding two sticks, makes her appearance. She attacks Another Hibiki with flames, and a drumhead flies out from her belt, enlarging and covering its body.

Fortunately, he nimbly struck the drum, and after the song ended, he also sent the enemy away.

'Stag Beetle! Spirit! Rider Match!'

"Watch closely, my transformation is about to begin!"

Kuuga Red All-Powerful Form appeared, showing no fear in the face of Another Kuuga, which was several times larger than itself. After charging up, flames ignited beneath its feet, and it struck hard at the right moment. An ancient symbol appeared at the spot where Another Kuuga was kicked. After a few seconds of stalemate, Another Kuuga suddenly exploded.

"Card! Sword! Rider Match!"

"I will seize the trump card of fate!"

A blue card light screen appeared in front of him. After passing through it, he was in a completely new form. Kamen Rider Blade held the Awakening Sword, drew out a few cards, slashed them, and then stood on Another Blade, sending him down the same path as his companion.

"Engine! Policeman! Rider Match!"

Come run a lap with me!

A tire flew out from somewhere and pierced the knight's body at an angle, revealing the bright red armor.

Kamen Rider Drive stretched his body, and a red car appeared. Red phantoms surrounded Otherworld Drive, and Drive, riding in the car, launched continuous attacks on him, finally ending with the enemy's destruction.

"Card! Camera! Rider Match!"

"I'm just a Kamen Rider's passing by, remember that!"

As Sachi, transformed into the Crimson Knight, spoke these words to the empty battlefield.

Fortunate. "..."

Tsukasa Kadoya: "..."

Eiji and Ankh: "?"

Squeezing the Three Idiots: "?"

He coughed a few times, then turned his head awkwardly. "Oops, I wiped out all the enemies without even realizing it. I forgot we didn't have Another Decade."

Just as Xing was feeling extremely embarrassed, Tsukasa Kadoya, who had transformed into his Build form, walked up and patted her on the shoulder.

Bild in Decade form and Decade in Build form standing together don't look out of place at all. It would be even more perfect if they could switch their belts.

"Don't play here!" Xing angrily punched him. "What do we do now? Where's Pandir?"

With a flick of his finger, Kamen Rider Decade Xiaoming conjured a dimensional screen, teleporting everyone present to an unknown wasteland.

A dark mass of enemies appeared before them. Tsukasa Kadoya explained, "That guy set up a barrier around his base, so I can't go in directly. There are also these enemies he summoned outside. I can't get in without taking care of them."

"Leave it to us!" Eiji and the others volunteered, transforming into their strongest forms and bringing out their respective vehicles.

Wait a minute, where did that vending machine come from? And Ryuga, why are you all using Mechanical Creator? Hasn't Sento made any other series of motorcycles?

Xing sighed softly, took out two brand-new full bottles, thought for a moment, then replaced one with the old one, shook it a few times, and inserted it into his belt.

"King! Watch! Rider Match!"

"Rider Time!" Kamerider Zi-O!"

"It feels like it might work."

Fortunately, he removed the motorcycle watch face embedded in his arm, transformed it into a motorcycle rider, and charged towards the monster army with the others.

Amidst the raging flames of war, Tsukasa Kadoya and the others deliberately drew fire for Sachi, allowing her to enter the central palace.

Zi-O in his basic form rode his exclusive vehicle through the palace gates and arrived before the Secondary Chaos Emissary had stolen the Ohma Power from this timeline.

The magenta and dark red compound eyes met, and both understood that this would be the final battle.

Author's Note—

This chapter was incredibly demanding! The official guide provided nine combinations for twenty Kamen Rider, but I managed to create eleven myself. It was exhausting...

The key point is that this chapter has reached a new record for word count, with a total of 8,117 words in the main text!

To explain why Sachi couldn't use the Knight Combination before, when she transformed, due to her own characteristics, she connected with the power of other Riders who had not yet been born in the Honkai World, thus enabling her to transform.

In the Knight World, the power of those knights was stolen by Pandir, and since the cell phone couldn't connect to a signal, it naturally couldn't transform.

Although the Honkai World is temporarily connected to the Knight World, they are quite far apart and the signal is not working.

After Sento brought Build's Rider Watch, Sachi finally connected with the power of the Riders in the Honkai World, and the Knight Combination was restored.