Fate/Grand Order - Billy's Bizarre Adventure

=== Background ===
As Billy (Fujimaru Ritsuka) was warped into a alternative time-line resembling that of the timeline of Unlimited Blade Works, by way of an unsuccessful Rayshift from Chaldea. Billy himself was merged with the universe's version of Shirou Emiya. He was not conscious of this fact until Four Days after merging, by which he begun subconsciously desiring Rin Tohsaka of this Universe. The Story here essentially plays out the same way as the Unlimited Blade Words Route of Fate/Stay Night, with a few differences, creative liberties and connections to the Seventh Singularity of Fate/Grand Order's Story Mode. It also features the subconscious narration of Ritsuka Fujimaru as he experiences the life of Shirou Emiya. Here, Billy is essentially Shirou Emiya, with his personality slightly changed. A mixture of Shirou's and his own. His appearance is essentially that of Shirou Emiya, though with slight differences leaning more towards Ritsuka Fujimaru's Physique. His appearance later changes, resembling more of a mixture between Ritsuka Fujimaru and Shirou Emiya. (Basically just Gudao with brown eyes) Billy is without his memories prior to becoming this universe's version of Emiya, until the final episode. This Whole thing is basically a stupid version of Unlimited Blade Works to fit Rin Tohsaka into my head canon because I am of course, a filthy degenerate weeb. It is also good to note that this Billy version of Fujimaru Ritsuka is himself an Alternative Version of the Canonical Version of Ritsuka Fujimaru from Fate/Grand Order and its assorted manga and anime series.
=== Small Plan ===
Harmon Cycle
1 Chaldeans doing they thing
2 Mash and Billy go to New unidentified singularity
3 Mash and Billy get seperated during warp
4 Billy gets fused with Emiya Shirou of universe 0302200425022004, retains his memories,
5 Billy meets Rin Tohsaka
6 the two get betrayed by archer who is the future version of an Alternative Universe Billy, who is from the Billy-Verse Timeline- the fact he was fused is revealed
7 Universe 0302200425022004 Collides as Billy Fails to respond to this Pseudo-Singularity. The Grand order timeline , they return to Chaldea with The knowledge, and Billy's Emiya Shirou and Fujimaru Ritsuka memories are combined.
8 Rin Joins Chaldea and they aim to win the holy grail war to end the singularity
Cycle ends, story continues
9 story ends with mix of Heavens Feel and UBW ending, but with Chaldea intervention
10 they defeat holy grail and kirei, Rin's body gets brought to Babylonia to bring ishtar and eresh alive.
11 Chaldea begins rescue operation of Rin, and the Babylonia singularity plays out like normal but Chaldea knows about Rin and want to rescue her
=== ACT 1: ===
It's your average chaotic day at Chaldean Security, DaVinci doing her thing, Dr. Roman and Mash, the Loyal servant of Chaldea's own Trainee magus and Billy Paterson messing around with Fou, saving the universe one step at a time. Billy had just saved the world from the demon pillar of the Camelot Singularity. As soon as Billy and Mash had returned from Camelot, Chaldea was in disarray as a new singularity approached the Magus Security Agency. Dr. Romani Archaman reports that the new singularity had been detected, and urged Billy to investigate. 
=== ACT 2: ===
Entering the Rayshift Centre in order to approach the singularity Mash and Billy notice a temporal shift in the energy walls of the Rayshift. Suddenly, as they were warping through a total distance of 3000 years, the entire Rayshift began to shake, until they were essentially travelling through uncharted spacetime.
=== ACT 3: ===
Mash and Billy shifted towards each other as they had trained to do in they event they got stranded as they warped through spacetime But, unexpectedly they had been separated and Billy was travelling alone, not knowing where his servant had gone off to. It had appeared to Billy that he had been travelling alone through the Rayshift which had deviated from the intended destination. Of course, he had no contact from Chaldean Security, it was the perfect time not to.
=== ACT 4: ===
Suddenly Billy woke up in 'his' shed, with his Kouhai Sakura Matou. (JAMAIN HOLSTER YOUR GUN IT'S PLUTONIC) She urges him to come to school with her after she cooks him a nice breakfast. You see I have been living with Sakura now for two yea-- hold on... What the fuck is going on... 'Senpai? what's wrong?' wait I forgot. 'Sorry Sakura my plutonic female friend kouhai let's go' as the two plutonic friends escaped from Fuji-nee who demanded breakfast, and walked to school Billy's hand begun hurting like crazy, but only for a breif moment, Sakura was worried for her PLUTONIC friend, but he brushed it off. They arrived at school. As Sakura and Billy parted ways, Billy met up with his friend Issei "Based" Ryuudou. The school day passed. After school, Billy tells Ryuudou of his plans to stay at school for art and sport-- wait, sports??? I don't play sports wait a second. "Oh, Emiya why're you daydreaming" I hear an annoying voice. This tanned chick with short hair and annoying voice walks up to me with her party of girls, a scary one with glasses and a gentle boring one, walking among them is the Girl I admire, the school idol, Tohsaka Rin. "Oh Emiya-Kun Janai?" She says. "Tohsaka..." I remark. Issei and Tohsaka fight for no reason. Rin and her friends leave, Issei snarking about how he hates women. We say our own goodbyes as I do my thing after school.
=== ACT 5: ===
After about 5, I here loud clanging sounds from the court yard of the school. I walk closer. It takes me a while but I begin to feel the eyes of murderous intent upon me. I run by instinct. In that moment, I heard the words 
"DARE DA?!" 
As I ran. believing I've lost the homicidal presence follow me I stop for a breath. Looking behind me, I am exposed to another 2 equally distressing words 
"Oi bozuu".
I am pierced
By the mythical weapon, Dr. Romani and that caster were talking about. Huh?
'Gae Bolg.'
What?
I gasp for air.
I sit up, having been situated and sitting on the floor, with my clothing damaged. Left upon me was a beautiful red pendant, which shun brightly with penetrating red aura whenever light was cast upon it. I pick it up, strangely not questioning anything. I suppose my life must have been saved... Why am I not questioning this situation??? Huh? what do you mean? Nothing.' I rush home. It's already night. Suddenly the inhuman figure from the school yard appears. I reflexively take upon a rolled up poster left by the annoying Fuji-nee this morning, reinforce it's molecular integrity to that of cheap steel and deflect the Lance-mans attack, and stumble to my house's yard, and into my shed. I stumble around attempting to catch my breath, with my magic circuits activated I mistakenly place my hand upon a summoning circle drawn up by my father... Wait MY father?? Never mind. It lights up. I fall back, in surprise.
"と…あなたは… 私のマスタが?"
I look up.
Following a flash of light, a being many times brighter appears before me. Instantly she springs into action with her wind ensnared blade. The battle between the Lancer and this Saber is perilous, and they exhaust all but their most powerful attacks. As The spear user shouts a mighty 
"--Gaè Bolg--"
a golden light snares my vision and sets the air and surroundings aflame, the cause, Saber. 
"Ireland's Child of Light, wielder of the Lance of Causality Reversal, is that the best you can do?" The armoured woman would shout.
"Impossible..." the blue hornet remarks.
"Come at me, hound of Culainn!" Saber challenges.
Lancer does not move as Saber advances. He merely breaths, calmly. And opens his eyes.
”宝具”
The spearman begins, as he relinquishes his weapon to the ground. Saber stops. But it's too late...
"--リアーストラャード--"
Lancer's body convulses.
"Scourge of the Otherworld!" The beastly man-beast roars
His body grows and contorts, splits open like meat in an oven, turns inside out and deforms in every disgusting lament possible. Tendons and muscle fibres flurrying like snakes, yet growing in strength unimaginable all the same. His eye popping out of his his socket and teeth growing out of every part of his gums, he asks me 
"What do you think of this, Bozu?!"
"A hideous second Noble Phantasm, Child of Light?!" Saber hurls in disgust.
"That's right... and you get to be the next target..."
Cu Chulainn... wait how do I know this name??? Nevermind... Lancer, catapults his entire body, doggedly towards saber in a rage induced attempt to attack the Shining Knight. Saber dodges the wild boar with ease. As the two titans of immense power battle for their lives, I feel an immense quake tumbling through the air. The Mightiest of Arrows. The two Servants are drawn apart by what I can only assume to be a blast of immense power. 
"That's enough, Archer" I hear an immensely confident voice emit.
Perhaps a voice too confident for her own good, Tohsaka Rin, the school's idol, appearing out of seemingly nowhere. 
"BaCk FoR mOrE!???? ArChEr!?!??!?" 
The increasingly crazier hound, Lancer growls. Tohsaka Rin, seemingly frightened, jumping back like you would when you see a grotesque spider or insect.
"What in the world has happened to you Lancer, you seem more like a Berzerker!" The red-clothed girl would remark 
"I mIgHt As WeLl Be, HaHahAHhaHhah!!" the dog barks. 
"Archer, get that crazed fiend!" Tohsaka shouts.
A dis-likeable red-clad iron knight materialises out of nowhere. He draws a bow, with a projectile poking out of it like a needle, growing to an immense length like a sabre-tooth. 
"It Is ToO lAtE, ArChEr!!!!" the hound coughs 
"You should reconsider..." 
he pulls the arrow like sword balancing on his bow back further as energy erupts out of it like a volcano. 
"CALAD---" (カラド---) 
The beastly Lancer gleams at the sword as Archer prepares to fire this world shattering attack. 
"ThAt'S tHe SwOrD oF fErGuS--" Archer cuts him off, triumphantly. 
"BOLG!!!!!" (ボルク!!!!!) 
Lancer is blown back. What remains of the monstrous tumour crawls away, barely alive... The blast was enough to deafen me for a whole minute, as we watched Lancer run away, casting last ditch effort Rune Magic to escape the incoming attacks from Archer and Saber.
Saber and Archer attempt to brawl, However I order Saber to reconsider. It seems Tohsaka had the same idea as Archer has long since disappeared, leaving only the scarlet princess to walk up to my surprise embraced body. "I think we should ally, in this holy grail war." She told me something along those lines, However this is not what she said, I was only listening subconsciously to understand the fundamental principals of the words she was making an attempt to communicate. I was simply too dazzled by all the things that had just occured within the last hour or so. Just before, I had no idea what these servants or how powerful they might possibly present themselves as, in all their dazzling glory. 
"Emiya-Kun, I'm sure you're either confused or just wondering what the hell it is you've been dragged into, but don't worry, there's a place for people like you... It's called a church." she smirks at me.
"Why... would I need to go to church?" 
She chuckles at me. "Come on. He's a genuine FAKE priest, I'm sure you'll detest him as much as I" 
=== Act 6: ===
This pretty much plays out the same all the way from the church scene with Kirei in complete bewilderment at the fact kiritsugu had a son (adopted though), the illya fight, Emiya getting injured, and Tohsaka greeting Emiya when he wakes up in surprise.
=== Act 7: ===
After all that, and with Saber resting at home, Tohsaka asks me about magical crests. 
"I don't have a magical crest." I would tell her. 
Tohsaka makes a doubtful expression, and gets too close for comfort, towards me as I flinch. 
'W-w-what are you doing??' 
I draw back and retreat from her as though I'd just fired a gun, mistakenly. My vision blurs and I begin to feel as though my face has been set a flame. Am I blushing?? She forcefully grabs me, she's surprisingly strong for her appearance. Though it's not as though I'm THAT strong to begin with... Without warning she applies pressure on some nerve on my arm that forces it to jolt with pain. I try to move but she stops me. Her expression gives me the impression that she has been focusing on my arm rather than how I have been behaving or how I've felt about her giving me so much pain. 
"There!" She chuckles, "You DO have one after all!"
I quickly ratchet my neck towards my arm like the hinge of a mouse trap. And am greeted by a glowing display of Runic inscriptions, Celtic and Viking-like patterns covering my arm, all glowing like beaming street lights at night. As though I had been tattooed with neon embedded ink. I could even read some of it, but really I'm too shocked to even try. I'm too shocked to even notice the blazing burning sensation now radiating from my arm. Kiritsugu never gave me a magical crest, despite what I am seeing, I know that with absolute certainty that HE never gave me one. But that just can't be true according to my eyes.
"I knew it all along, No magus can possibly lack a magical crest, You actually had me worried there... Though..." Tohsaka stops in deep thought.
She ponders for a while.
"What is it?" I shake at her, my heart racing, not truly having anything witty to say as a result of this immense shock.
"Oh, don't worry about it for now..." She says this with a under tone of what might be envy or angst towards me. But I guess I will play along with 'not having to worry about it for now.' 
I look upon the glowing patterns and inscriptions, Gazing at their beauty. The patterns upon my arm fill me with a sense of keen curiosity as though I'm seeing something entirely alien. It's nothing like the crest Kiritsugu had... 
"I assume you don't know how to use any of the magic embedded in your arm her, but worry not, for I shall teach you..." She gleams at me...
"Yes I know that... Hmm, so what? I can still teach him! It's the least I can do!" Seemingly, arguing with her servant.
She looks back at me.
"What kind of magic did your father use?" She stares down at me...
I don't know how to answer... I think for a little while.
"You don't know?" Tohsaka accuses of me
"No! it's just that..."
"Speak up!"
"I don't remember..."
"Well, what ever, I guess it can't be helped, we'll find out what's in that crest eventually..."
Assuming the magics my father had are even in this crest...
"I'm only going to teach you fundamental basics, by the way, you're still my enemy, so don't get the wrong idea!" She spits out and storms out of my house. 
I'm just going to go straight to bed then I'm exhausted!
=== ACT 8: ===