I don't own Kamen Rider or Fate Stay Night. All are owned by their respective owners.

(Final Vent)

Prologue: Where it all ends and where it all begins

Fuyuki City Bridge:

Third person POV

Currently the Fuyuki Bridge was in complete ruin. The paved roads of the bridge had spider web like cracks, cars where reduced to scrap metal and some were set ablaze. This was caused by an attack of a group of Mirror monsters known as Raydragoons. There were no signs of life in this place… except for two.

One was a man in his early twenties (AN: Not really sure what his age is) with short black hair and eyes. He was wearing a black shirt with black leather coat and matching leather pants. His name is Ren Akiyama, Kamen Rider Knight and he was currently running towards another person.

The said person was a boy in his teenage years, with Auburn hair and golden eyes. He was wearing a simple white shirt with blue sleeves and simple blue jeans. This boy's name is Shirou Emiya, Kamen Rider Ryuki and right now he was leaning on a car with a large hole in his chest, blood slowly dripping from it.

"Shirou!" Ren shouted to him, trying to keep him awake. "Shirou hang on, I'll get help!" he cried out and Shirou shook his head, indicating he was saying no. "It's no use Ren… I'm going to die." Shirou said, his life slowly slipping away. Ren only stared at him, devastated that it was the truth.

"Shirou…" Ren whispered and Shirou struggled to look at him, but was able to. "You know Ren… I saved a life today…" he said remembering the little girl he saved from the Raydragoons earlier. "Yah… you did." Ren spoke in a comforting tone for his dying friend.

"Hey Ren, where friends right…" Shirou asked and Ren responded, "Yah, we are, aren't we." Ren said in a realized tone and started to cry with the realization. "So… will you listen to your friend's last request?" Shirou asked and Ren nodded as his response. "End this war, win, close the mirror world and bring back Eri-san."

"Alright… I promise." Shirou smiled at that, happy his friend will go on. "Go Ren; beat that bastard Kotomine and stop Shiro... for Yui's sake." Ren nodded and started to stand, walking away from Shirou to fulfill their promise.

Shirou stared the retreating form of his friend while remembering the past events that lead to this.

(Flash back)

"My name is Shiro Kanzaki." Shiro introduced himself to Shirou.

"Take the deck." Shiro Kanzaki said to Shirou giving him a blank Advent deck.

"What's that sound?" Shirou said while hearing a strange ringing sound.

"NO STOP!" Shiro yelled after watching a strange Kaijin pulling a man in too the mirror.

"If you want to stop the monster then Henshin!" Shiro said to Shirou.

"With this, will I become a hero?" Shirou asked Shiro with a hope filled tone.

"Henshin!" Shirou declared.

"So this is the mirror world?" Shiro asked himself in wonder.

"Sword vent."

"Rah!" Shirou yelled out while charging towards the Mirror Monster.

"Final Vent."

"Are you watching old man?" Shirou said to himself after defeating the Mirror monster.

"Who are you?" Shirou asked the mysterious black rider.

"I'm Ren Akiyama, Kamen Rider Knight!" the now named rider declared.

"Sword vent."

"Why are you attacking me?!" Shirou yelled in confusion.

"It is our destiny to fight one another!" Ren retorted.

"A dragon?!" Shirou cried out in awe and amazement on the mirror monster.

"I'm Yui Kanzaki." The cute girl introduced herself.

"Do you know where my brother is?" Yui asked hopefully.

"Take this card and contract with the dragon and help Ren!" Yui pleaded to Shirou.

"Accept me Dragon!" Shirou yelled out to the dragon.

"So your name is Dragreder." Shirou said to the dragon.

"Let's go partner!" Shirou said to his contract monster while inserting the final vent card in to his Drag Visor.

"Fight till the very end Shirou, until you're the only one left." Shiro told Shirou in an emotionless manner.

"I won't kill the other riders Shiro; I became a rider to protect the people from the mirror monsters!" Shirou spoke defiantly.

"Is my brother wrong?" Yui asked in sadness.

"Then I'll be your proof! I'll transform to defend the people!" Shirou told Yui reassuringly.

"So you're a rider to Emiya…" the young purple haired boy asked.

"Shinji!?" said in realization.

"Henshin!" Shinji Matou said while holding an advent deck with a golden crab insignia.

"I'm Kamen Rider Scissor!"

"Die Emiya! Go Volcancer!"

"Advent."

"Shirou stand aside!" Ren said to Shirou while charging at Shinji.

"Why are you fighting Shinji!?"

"You think I'm doing this for myself!" Shinji yelled at Shirou while they both clashed blades.

"Then why!"

"I'm fighting for Sakura!" Shinji reveling his intention to Shirou.

"You have out lived your usefulness Shinji." An old man said in a disappointed tone to Shinji.

"Zouken!" Shinji reveled the name of the old man.

"Henshin…" Zouken said while holding out a green advent deck with a bull insignia.

"I'm Kamen Rider Zolda!"

"Final vent."

"Shinji!" Shirou cried out while his friend took the barrage of missiles.

"Shi…Shirou… please save… Sakura…" Shinji pleaded while his life slowly faded away.

"Why did this have to happen?!"

"You can't save everyone Shirou. There will always be sacrifices." Ren said to the young man, trying to convince him.

"My brother is a magus?" Yui asked in confusion.

"Kanzaki, why did you give someone like Zouken an advent deck?!" Shirou demanded an answer from Kanzaki.

"Yoh Shirou!" a strange young man called out.

"Tojo Satoru!" Shirou said, identifying his friend.

"Henshin!" Tojo said while bringing out a blue advent deck with a tiger insignia on it.

"I'm Kamen Rider Tiger!"

"Come Destwilder!"

"Advent"

"I'm going to save Sakura. Will you help me Tojo, Ren?"

"Show yourself Zouken!"

"What troublesome children." Zouken sighed in irritation.

"Come out Byakuya!" Zouken called out for his so called son.

"Henshin!" Byakuya declared while holding a brown advent deck with a gazelle insignia.

"I'm Kamen Rider Imperer!"

"Shirou we'll deal with Imperer, go to Zouken and get Sakura." Ren told Shirou, preparing to fight Byakuya with Tiger.

"So… you have arrived Emiya."

"What is this…?" Shirou said in horror after seeing Sakura being raped by Zouken's worms.

"Sempai… don't look…" Sakura said in shame while covering herself with her arms.

"I'll kill you Zouken!" Shirou yelled out in rage.

"Final vent."

"No! I need to live! I need to see her again! Justeaze!" Zouken cried out in anguish before vanishing into particles.

"I just killed a man…" Shirou wishpered in horror.

"It's the end Imperer!" Ren yelled while he and Tojo activated their final vents.

"I'm finally… free~" Byakuya said in satisfaction.

"Sempai?"

"Let's go home Sakura…" Shirou said while hugging her with tears flowing from his eyes.

"I killed someone Tojo!" Shirou cried out in horror.

"If you want to be a hero, sacrifices must be made!" Tojo said, trying to convince Shirou his ideals where wrong.

"I don't believe that!" Shirou screamed, still not acknowledging Tojo's reasons.

"I don't want to be a rider anymore!"

"Shirou can't be the hero, I'll have to be in his place." Tojo said to himself. Hardening his resolve.

"I will end the fight between the riders and this war!" Shirou declared with a new resolve.

"Who are you?!" Shirou yelled out at the new mysterious rider.

"I'm Kamen Rider Gai…" the now named rider spoke in an emotionless tone.

"I have no ambition in this war… I only fight because I was asked to, by Shiro Kanzaki." Gai reveled to a stunned Shirou

"Kill him Metalgelas!"

"Advent."

"Nii-chan, are you a magus?" Yui asked her brother after not seeing for years.

"No Yui, I'm a sorcerer."

"Your brother is a what!?" Shirou along with Sakura yelled out in shock after what Yui reveled.

"I created the path way to the mirror world, the new phantasmal race, the mirror monsters and the advent decks via the first true magic, the denial of nothingness." Shiro reveled to them.

"This is all for Yui's sake!" Shiro declared.

"We finally meet, son of Emiya. I 'am Kirei Kotomine." The strange priest introduced himself.

"Henshin!" Kirei declared while holding out a purple advent deck with a cobra insignia.

"I'm Kamen Rider Oja!"

"Seeing you die will be the sweetest thing, Shirou Emiya, come Venosnaker!" the mad priest said with an emotionless tone yet gave a sadistic smile.

"Advent."

"It seems your enjoying your time with these mongrels, Kirei." The blond man spoke with arrogance.

"Henshin!" the blond man declared holding a golden advent deck with a Phoenix insignia.

"Who are you…?"Tojo asked the Golden Rider as he prepared for the inevitable conflict.

"I'm the king of hero's Gilgamesh, but for now you may call me Odin!" the now named rider shouted with arrogance dripping from every word.

"Time vent."

"This was unexpected…" Shiro said while observing Gilgamesh.

"Do you want to help your beloved?"

"Yes!" Sakura said to Shiro with unwavering determination.

"Then take the deck." Shiro handed Sakura a white advent deck with a swan insignia.

"Sakura?" Shirou said in confusion.

"Henshin!" Sakura declared while holding her advent deck.

"I'm Kamen Rider Femme!"

"Come Blancwing!"

"Advent."

"Who gave the Odin and Oja advent decks to those two?" Shiro pondered at this sudden, unexpected development.

"I'm the ruler of the mirror world, Agito!" the strange red armored being reveled to all riders.

"So you still exist, will of the mirror world."Shiro asked the other Agito while reveling his true identity.

"I'm Kamen Rider Agito!" The real Agito introduced himself.

"Let's go everyone!" Shirou told all Kamen Riders and clashed with the other Agito and his army of mirror monsters.

"Rider Kick!" Agito and Ryuki cried out together.

"Remember this Kamen Rider's! I will return and collide the real world and mirror world and rule the new world! No one will stop me! Not the riders, not Gaia, not Alaya not the Types! I WILL…!" Mirror Agito declared while slowly dissolve to nothingness.

"Remember what we, Kamen Rider are Ryuki." Agito said while bidding farewell to his fellow riders.

"I will… Agito!" Shirou said happily.

"Nee-sama…" Sakura spoke darkly to the pigtailed girl.

"Sakura…" replied by the pigtail girl.

"Rin Tohsaka is your sister!" Shirou and Tojo cried out in surprise.

"You serious…?" Ren and Yui said while comparing the two siblings

"Tohsaka run!" Shirou told Rin while he was holding of a group of mirror monsters.

"No I won't Emiya-kun." Rin replied while taking out a pink (or a variation of pink) advent deck with a manta ray insignia.

"Henshin!"

"I'm Kamen Rider Raia!"

"Come to my aid Evildiver!"

"Advent."

"Now this is interesting." Kirei said to himself, after seeing Rin became a Kamen Rider.

"I was the one who killed Tokiomi!"Kirei revealed to Rin like a mad man.

"I'll kill you, you fucking fake priest!" Rin cried out while activating her final vent.

"Now die Rin, oh~ and say hi to your dad for me." Kirei said to Rin with a sadistic smile.

"Get away from her!" Shiro yelled out while blocking Kirei's Veno saber.

"Emiya-kun, Sakura, Ren-san and Tojo-kun…" Rin said in disbelief when the four defended her from Kirei's onslaught.

"I need some extra help, come Metalgelas!"

"Advent."

"How did he gain Gai's contract monster!" Ren said while looking at what he thought was impossible.

"Stand aside Kirei, I shall handle these mongrels!" Gilgamesh declared while taking out his advent deck.

"Now die!" Gilgamesh yelled while a large number of golden portals appeared behind him.

"I won't lose to you, king of hero's!" Shirou defiantly told Gilgamesh while inserting a strange advent card.

"Trace vent."

"Impossible he traced all my Noble phantasms!"

"This is my new power?"

"This ends now Gilgamesh!"

"How, can a mere mongrel beat me…?" Gilgamesh said while he faded into golden partecils.

"Well done Shirou." Shiro congratulated him on defeting Gilgamesh.

"Take this as my thanks'." Shiro then handed an advent card that had a golden wing image on it.

"Survive?" Shirou looked at the card with wonder.

"Now I must take up this role." Shiro spoke with irritation.

"Henshin!" Shiro declared while holding out the Odin advent deck.

"I 'am now Kamen Rider Odin."

"The last rider will face me in the end and win the omnipotent wish!" Shiro declared to all present riders.

"The game master himself joins in! That's just cheating!" Rin cried out.

"Now this is such a magnificent scene!" Kirei said with glee, witnessing the death and destruction of Venosnaker and Metalgelas was causing in Homurahara Academy.

"Run everyone!" Shirou said while he, Ren and Tojo where holding off both Venosnaker and Metalgelas.

"No!" Tojo screamed while running and shielding a group student that tripped while running away from Venosnaker.

"Tojo!" Shirou screamed in horror, witnessing Tojo being bitten to death by Venosnaker.

"In the end, I was the naïve one…" Tojo lamented on his actions.

"Tojo~" Shirou cried while holding on to his dying friend.

"Shirou… are they safe?" Tojo asked his friend.

"Yeah… they are… you saved them Tojo…" Shirou answered, still crying over his friend.

"That's good… Neh Shirou… did I… become a hero?"Tojo said while his last breath left him.

"TOJO!" Shirou cried out, his friend deathly still on his arms.

"I will never forgive you! KIREI KOTOMINE!" Shirou told Kirei while holding the survive card.

"Survive."

"What is this?!" Kirei said in disbelief after witnessing Shirou's new transformation.

"Shirou…" Ren whispered in amazement.

"Come Dragranzer!"

"Advent"

"This isn't over…" Kirei said while limping away, after Shirou used his final vent.

"We should give Tojo a proper burial." Ren said with sadness.

"Tojo~\Tojo-kun…" Both Rin and Sakura grieved in front of Tojo's grave.

"Why…! Why couldn't I save him? I couldn't even save my friend!" Shirou cried in anguish in front of Tojo's grave.

"Don't give up Shirou! Continue to be the hero you wanted to be! Not only for your sake, for your father, for Tojo, for Rin, for Sakura, for Yui for all those who you couldn't save! See it to the very end!" Ren said to Shirou trying to help his broken friend.

"Ren…"

"Who would have thought I'll get a chance to kill Tokiomi's second daughter. Oh~ I wish Kariya would see this." Kirei spoke while slowly walking to Sakura's defenseless state.

"Final vent."

"NO SAKURA!" Rin cried out and defended her sister from Kirei's attack.

"Why…" Sakura said in disbelief on her sister action.

"No matter what happened you're still my sister…" Rin said to Sakura while her life was slowly slipping away.

"Nee-sama~" Sakura said to her dying sister, her tears slowly falling.

"I won't forgive you…" Sakura said, gently laying her sister to the ground and bringing her advent deck out.

"Come at me… Sakura Tosaka!" Kirei said while summoning his Veno saber.

"Raaaahhhhhhh!" Sakura yelled out while charging towards Kirei.

"This ends now." Kirei said while Sakura struggled to stand once more.

"Final vent."

"SAKURA, RIN!" Shirou yelled, running towards to the two.

"Shirou/Sempai~" both girls said while seeing the boy they loved coming to their aid.

"Shirou tend to them. I'll deal with Kirei!"Ren said while bringing out the survive card.

"Survive."

"So you obtained the same power as Shirou Emiya's." Kirei said while observing Ren's Survive form.

"Rin… Sakura…" Shirou wishpered in horror and sadness while looking at their wounds.

"It's okay Shirou. Don't blame yourself." Rin assuring said to him.

"You can't save them." Shirou suddenly heard a voice from somewhere.

"Sempai… thank you for everything. Thank you for all you have done for me." Sakura said to him, her voice slowly growing fainter.

"You never had the chance to be a hero." The voice said yet again.

"I love you Shirou/Sempai." Both said in unison while their lives faded from the world

"YOU CANT SAVE ANYONE!"

"You shall do nicely." Kirei said while bringing out a contract card and faced it to the charging Evildiver.

"Contract."

"So that's how he obtained Metalgelas." Ren said in realization.

"If you want them back, simply win the war Shirou." Shiro Kanzaki said to Shirou temptingly.

"Yah… I can bring them back… cant I…" Shirou said in an emotionless tone.

"Shirou, what the hell are you doing!" Ren cried out while dodging and defending himself from Shirou's attack.

"Fight… fight… fight…" Shirou said in a broken, trance like state.

"Now this is INTRESTING!" Kirei yelled with glee. Witnessing Shirou's broken state.

"Shirou…" Ren struggled to speak while in a helpless state on the ground.

"Shirou stop!" Yui cried out while in between Shiro and Ren.

"Move Yui…" Shirou said to her, while his sword was still pointed on her chest.

"NO SHIROU! Do you really believe this is what they want! Rin-chan, Sakura-chan, TOJO-kun wouldn't want you to be this! Don't let my brother manipulate you!" Yui yelled out to Shirou, trying to get him back to his senses.

"I…I…AHHHHHHH!" Shirou screamed while on his knees, looking at his trembling hands.

"Hello there me!" The person who was a splitting image of Shirou greeted the real Shirou.

"Who the hell are you!" Shirou demanded Dark Shirou.

"I'm you! I'm Shirou Emiya!"

"I'm no longer the illusion in the mirror. I exist as the strongest among other rider!" Dark Shirou said with malevolence in his voice.

"HENSHIN!" Dark Shirou said while bringing out an advent deck with a black dragon insignia.

"Ryuki?!" Shirou said in confusion after witnessing his counter parts transformation.

"There two Shirou's!" both Ren and Yui said with surprise and confusion.

"I 'am the you that should be! I 'am the you that could never be denied!" Dark Shirou cried out while he clashed his blade with the real Shirou.

"I will never accept you! You are an illusion, a lie, a me that should never be!" The real Shirou retorted to his others claims.

"RAAAAAHHHHHHAAAA!" both Shirou yelled preparing their final vents.

"It's my lose." Dark Shirou said in defeat, slowly disappearing to nothingness.

"Shirou are you okay?" Yui asked her friend worriedly.

"Yah, Yui, I think I'm fine now." Shirou told her with a satisfied smile.

"Kanzaki…!" Shirou growled at the master of the rider war.

"You should all now the true purpose of the rider war." Shiro told Shirou, Ren and Yui, finally revealing his secrets.

"The purpose of the rider war was to save you, Yui." Shiro revealed. His cold persona was gone and replaced by saddened one.

"What the hell do you mean?!" Ren yelled at Shiro, agitated on his words.

"The Yui right now is her Mirror self fused with her original body." Shiro revealed and left all horrified with the revelation.

"My plan was to hand pick the entire participant, let them kill themselves and with the last rider, I would have used a puppet Odin and clam victory." Shiro spoke and his cold demeanor slowly returning.

"On her 20th birthday Yui will die." Shiro continued to unfold the events.

"Now fight, fight till one is left and the last rider shall face me!" Shiro declared while raising his arm towards the sky.

"No! I don't want this! I don't want to be saved like this!" Yui yelled with all her might, leaving Shiro in shock.

"If you want her back then meet me in the church. I'll be waiting Shirou Emiya!" Kirei said while holding an unconscious Yui.

"Go Shirou I'll take care of this!" Ren said to Shirou while holding of Evildiver and Metalgelas.

"Yui!" Shirou yelled, looking at a chained Yui.

"Even if you manage to beat me, you have no means to save the girls Shirou Emiya." Kirei said to Shirou for once annoyance present in his voice.

"AAAAHHHHHHH!" Yui's screamed due to the intense pain she was feeling.

"Shirou please… stop my brother… please save him…"

"I promise Yui…" Shirou wishpered with determination while holding the lifeless girl in his arms.

"She's dead…" Ren said looking at Yui's lifeless form, a tear slowly fell from his cheek and fell to his knees.

"There is no point anymore…" Shiro said to himself. The light in his eyes was no longer present.

"Go kill them all…" Shiro commanded the hundreds of Raydragoons.

"My god!" Shirou yelled, seeing the endless Raydragoons killing everyone in Fuyuki Bridge.

"NO!" Shirou screamed, seeing the Raydragoons was about to stab a little girl.

"AHHHHH!" Shirou cried out in pain while taking the blow for the little girl.

"Run…"

"Hens…shin!" Shirou held out the Advent deck while blood flowed out of his mouth.

"Shirou… your…"

"Let's go Ren!"

"Final Vent"

"RAAAAHHHHH!"

(Final Vent)

Shirou watch his friend leave until he was out of sight. Looking up at the sky, his vision blurred until he could not see anymore. He breathed his last breath and silently said his last words. "I… have no regrets."

Thus ends the tail of the legend of the rider war. Yet fate had other plans. For this ending will give birth to a new beginning. The legend will take up his sword once more.

Chapter End.

(Final Vent)

AN:

Hey guys this is Berserkerzero7 bringing you a new story, a Fate Stay Night and Kamen Rider Ryuki crossover. In all honesty I was really shocked at the lack of Fate stay night and Rider crossover and most of the fic's in these crossovers are dead. So I decided to make one myself.

First I want to point out that this is a complete AU. So I won't be following the Nasuverse rules to much, only some of it. This is basically the Nasuverse in the Kamen rider universe.

Now on to this rider war of mine, as you have read most of the participants is the Fate stay night cast. Which the overall flow of the war is an AU. As you have read there are some holes in the story that left out some detail. That was due to the entire POV was directed to Shirou. So there would be some events that he had not known like the Identity of Gai and his death to name one.

Lastly I'm going to make a poll on which servant Shirou will get. I like Saber and all but there are other servants that I want to write about. So vote for the servant you like.

Another thing, some of the other servants will not be canon. Some will be from the other franchise.

Oh yah this will be a harem fic. I hate single parings.

This is Berserkerzero7 signing off.