I don't own Fate/Stay Night or Kamen Rider and they belong to their respected owners. Also, this is a Two-In-One One-Shot.
Dragon Arthur:
Shirou opens the Ride Book.
King of Arthur!
Toaru kishi-ou ga furi orosu kanzen chouaku no hitotachi.
"Poetic Justice?" Saber tilts her head. "Is that how people see me?"
Shirou inserts the Ride Book into the left empty slot of his Seiken Driver then pulls out the Kaenken Rekka.
Rekka Battō!
Saber appears in a library surrounded by flames of the Brave Dragon and King of Arthur Wonder Ride Books appearing opened behind him. He performs an "X" slash before a dragon and a larger version of Kingexcalibur released from the Wonder Ride Books.
Nisatsu no hon o kasaneshi toki seinaru tsurugi ni chikara ga yadoru!
The dragon circled around Saber as the large Kingexcalibur floated above him. Saber raised his hand having the actual Kingexcalibur landing on his hands. Saber now with armor pieces on his left arm based on the story of King Arthur or to individuals who truly knew her, the story of King Artoria.
Wonder Rider! Dragon! Arthur Ō! Futatsu no zokusei o sonaeshi yaiba ga togisumasareru!
"Tsk! Do you honestly believe you can defeat your king!" Gilgamesh glowered at the Rider.
"You're nobody's king, and if I did follow a king it would be King Artoria. Right now she gave me her power," Shirou smirked under his helmet.
"You do know that's not her true power, right?" Gilgamesh says as opens a few gates behind him.
"Her true power comes from her story, but it's the story that gave you power!" Shirou stated. "If your story wasn't written then you would have been a nobody. Saber believes in my strength just like she believed her comrades, the Knights of the Round Table, allowing her to conquer any foe!"
"Then you just die!" Gilgamesh threw his treasure at Saber.
As a surprise to everyone, Saber summoned a large version of Kingexcalibur and started slicing through all Gilgamesh's swords.
Jakin! Jakin! Jakin! Jakin!
The sword announces with every slash it strikes. The giant Kingexcalibur began to glow making Gilgamesh use his Arrow Protection Amulet to cover the attack.
Hissatsu Dokuha! King Slash!
Saber performed a downward slash on the energy shield and broke through pushing the King of Heroes back.
"You insolent mongrel!" An angry Giglamesh yelled.
Saber scans Wonder Ride Book in the slot of the side of Kingexcalibur.
King of Arthur! Kyodaina kenshi ga mewosamasu! King of Arthur!
The giant Kingexcalibur transformed into a giant mecha, King of Arthur, much to the shock of everyone. It started floating with the jetpack from its back.
"This is nothing but a joke! Don't you look down on your KING YOU MONGREL!" Gilgamesh started to summon more swords from the Gate of Babylon.
Saber just responded by slashing every Noble Phantasm that was coming towards him or at least making slashing movements for King of Arthur to copy as the giant Mecha slashes away the many Noble Phantasm.
Jakin! Jakin! King Slash!
"Now it's time for me to cut you down!" Shirou declared and before he could do anything his body was stiff.
Sword Change!
The kama from the left side of his waist began to move upward and onto his back creating a blade connecting to his back.
"I didn't know I could be the sword!" Shirou exclaimed as he floated to King of Arthur's right hand.
Kamen Rider Saber!
King of Arthur then charges both Saver Saber and King Calibur to deliver two powerful slashes to Gilgamesh.
King Slash!
Gilgamesh summoned his Enkidus to cover the attack as King of Arthur delivered the powerful slashes breaking through the Enkidus'.
"Impossible!" Gilgamesh looked wide-eyed.
Saber got off King of Arthur's hold and jumped forward towards Gilgamesh!
"I told you I cut you down!"
Hissatsu Dokuha! King Slash!
Saber makes two powerful cuts with the Kaenken Rekka and the Kingexcalibur at Gilgamesh that the golden king didn't have a chance to react to.
"Gahh!" Gilgamesh screamed as the powerful slash made contact with him.
When the dust cleared, Gilgamesh had a large gash on his chest.
"Damn you…" Gilgamesh muttered.
Gilgamesh opens a gate, summoning Ea, as Gilgamesh was about to grab hold of his handle a voice was heard.
"I don't think so!" Shirou shouted as he sliced the golden king's arm off.
Gilgamesh holds his severed arm with blood pouring out of it.
"You should've known, your highness," Shirou smirked under his helmet. "I'm the one who decides how this story ends!"
~/~
Fantastic Lion:
Shirou brought out Peter Fantasista's Wonder Ride Book and a new one based on a mythical creature, the Tenkuu no Pegasus Wonder Ride Book.
Peter Fantasista!
Tenkuu no Pegasus! Katsute Souhaku no Tsubasa o Motsu Shinjuu ga Ten-kara Kagayaki Maiorita.
Deep in the shadows, the Servant known as Rider was watching and was surprised that boy Shirou had had a book about Pegasus. After all Rider's real name is Medusa, and Pegasus who was a gift from the Sea God Poseidon was her son. He was even her Noble Phantasm. But to see the love of her true Master about to use her son's power. It caught her interest.
Back with Shirou, Blades inserts the two Ride Books onto the left and right empty shelves of his Seiken Swordrivers and pulls his Suiseiken Nagare out of his Driver.
Nagare Battō!
Blades appear in a library surrounded by surging water with three of the Wonder Ride Books appearing open behind him. A blue lion, blue pegasus, and a teal-colored pixie letting out green pixie dust came out of their respected Ride Books.
Aoki yajū (Aoki yajū no) no tategami ga (Tategami ga) sora ni nabiku~! (Sora ni nabiku!)
With Blades already in his default armor, the blue lion disappears as the pegasus and pixie circle around him. Both entities stop circling around him and give Blades his extra armor. The pixie formed the usual armor piece to his left arm. Now the blue pegasus gave Blades a new armor piece to his right arm and completed the transformation.
Fantastic Lion~!
His right arm had more of a steel blue color than his other armor pieces. The ride side of his helmet had a small pegasus wing. His shoulder had a model of the pegasus head with a pegasus wing poking out of his back. It also had a shooting star representing its speed and constellation.
Nagare sansatsu! Konpeki no tsurugi ga kiba wo muki ginga wo seisu!
"What is this?!" True Assassin questions him.
"You'll pay for what you've done," Shirou glared under his helmet. "I didn't think much of this war but now with you killing innocent people."
"You don't understand what you're saying, boy." True Assassin said.
"I heard there may be a Servant here, it's one thing going against a Master, but you crossed the line involving my friend and his home!" Shirou shouted.
"Tch." Shirou couldn't tell but he's pretty sure the Assassin scoffed.
"Let's go, Saber!" Shirou shouted.
"Yes, Shirou!" Saber complied as they both charged at the masked Assassin.
So they fought both Master and Servant, fought the dangerous Assassin. And knowing by his cloak and wearing a mask, he must have been a skilled assassin. But he's facing a powerful swordswoman and a Kamen Rider with Wonder Combo and they both knew he had to be stopped.
"Saber!" Shirou calls out to her.
"Yes, Shirou." Saber looks at him wondering what he needs.
"Saber with your honor as a knight will you help me protect my home?" Shirou asked her.
Saber looks at her Master for a few seconds before giving him a beautiful smile, she gets on one knee with her sword stabbed to the ground.
"It would be my honor, Master." Saber said with sincerity.
"You fools will pay for this!" Six knives were thrown at them but both Master and Servant easily knocked all knives thrown into their way.
Saber blocked the knives as Blades inserted Suiseiken Nagare into his Driver before pulling it out, activating his finisher.
Hissatsu Dokuha! Nagare Battou!
Pegasus!
Lion!
Peter Fan!
Sansatsu Geki!
"Hydro Vortex!" Shirou shouted.
W-W-W-Water!
Blades summons a whirlpool of water that lifts the Assassin Class Servant up.
"Ha!" Saber jumps to the height of Assassin and slashes through him.
"Gah!" Assassin shouted as blood spilled from his stomach.
"Finish it Shirou!" Saber shouted.
Blades then levitates before sending a slash to Assassin, thus defeating the Assassin in question with a watery explosion.
Blades back was to Assassin fallen form, he turns to Saber, "Let's head the Temple!" Shirou says.
"Yes, Shirou!" Saber nodded and followed her Master.
AN: Here's my one-shote with Fate/Stay Night. To be honest I wanted to use King of Arthur in FGO for the Camelot movie but I don't know any of the scenes so I'd used UBW. Both one-shots were short but they were short so I thought I would put them in one chapter. They're not my best work but this what you got.
