Gilgamesh growled when the black vortex, which had manifested next to his hip, started to quickly expand and engulf him.

"You malformed abomination!" he bellowed, "You think you can swallow me-"

His next words were muffled when the vortex proceeded to swallow him.

"Mmhph! Mmpphhh!" despite his predicament, Gilgemesh's eyes were ablaze with fury, refusing to accept this ludicrous way of perishing.

Throwing his hand forward, he used Enkidu: Chains of Heaven and latched onto Shirou to anchor himself. He tugged on the chains, managing to slightly drag out his head and arm.

Unfortunately, it seemed that Gilgamesh had miscalculated, not taking into account how exhausted his opponent was, which resulted in Shirou tumbling forward, en route to crash into him.

Which wasn't part of the plan.

"Wait! Stay where you are!" Gilgamesh shouted

And if he were able to, Shirou would have wholeheartedly obliged, but at the moment had little means to stop himself.

Luckily, Archer was there to save the day, shish-kebabing Gilgamesh's head with an arrow, before rushing forward to grab his alternate younger self- oh wait no, he tripped.

"Oh shi-" was the last thing Archer said before colliding into his younger self and plummeting the both of them into the void.

(Later)

"What the hell did you do!?" Shirou roared, his voice echoing throughout the vast expanse of his Unlimited Blade Works, where he and Archer had found themselves in.

"How are you even here? I specifically remember you being impaled by fifteen different swords the last time I saw you. Why are you still alive?"

"People don't always die when they are killed." Archer stated

"That doesn't make sense!" Shirou snapped, Archer's blasphemous statement going against his very soul.

"You don't make sense!" Archer glared, "What were you thinking, getting dragged forward like that? You couldn't just hang on for like, ten seconds? Your incompetence is why we're both here."

"You're the one who pushed me! You tripped! What kind of servant even trips?"

And just when the situation was about to reach its breaking point-

*Boom*

Suddenly, a cloud of dirt kicked up to the side of them, where a voice boomed from inside it.

"Hello there-" the boisterous voice suddenly dissolved into hacks and choking noises.

"*Cough* *Cough*, Oh my god," the voice wheezed out, "Why do you have dust in your soul? I wouldn't have done my dramatic entrance if I knew people had dust in their souls."

Emiya Shirou and Emiya Shirou turned their heads to the sound of the coughing, where a bearded old man stood, leaning his weight slightly on a cane and holding a fist to his mouth.

"Hwack!" the old man proceeded to spit out a glob of phlegm onto the floor of Shirou's Unlimited Blade Works, the literal manifestation of his soul, before grumbling and wiping his mouth with the back of his hand.

While Shirou didn't know what to think of the man in front of them, Archer's face contorted into one of pure dismay, like he had sucked a lemon.

"Fuck."

(Later)

"So boy, how do you like the idea of saving the world?" Kischur Zelretch Schweinorg, the practitioner of Second Magic, offered to Shirou

Shirou was confused.

"Don't do it. If you are ever going to listen to anything I say, do it now. If you get involved with that deranged troll right there, you'll regret it for the rest of your life." Archer said, his tone deathly ominous.

"You seem oddly concerned for me." Shirou couldn't help but note

"I couldn't give jack about what happens to you. But due to being within a fifty meter radius, I'm afraid that I'll end up being dragged along into whatever nonsense he has in store for you."

"Glad to see you care."

"I don't."

"That was sarcasm."

"I know."

"So have you come to a decision yet?" Zelretch interrupted, "I'll have you know that you don't have much time left."

Shirou cocked an eyebrow, "What, is this some sort of time limited offer?"

"No, I mean in the fact that you only have thirty more seconds before you get ripped apart and torn to shreds inside the void left behind by Holy Grail." the way the old vampire discussed Shirou's impending demise made it seem like he was talking about the weather.

"Oh yeah, I forgot about that- wait say that one more time?"

"I said you have thirty seconds- well now twenty, before you get brutally mangled into holy grail feces."

Their surroundings rumbled, as if to confirm Zelretch's words.

"Oh." Shirou didn't even stop to think about it, "I guess it's time to save the world."

"Wait! You stupid piece of uterus poop-" Archer tried to protest

"Ah good! I knew you wouldn't disappoint me Emiya Shirou." Zelretch said in approval, "Now, hold on, let me make some changes so you fit right in with your new world." he then proceeded to twirl his cane and blast Shirou with a magic beam of energy.

"Gah! Son of a-" Shirou clutched his head in pain as a sudden influx of information crammed itself into his brain.

Chaldea. Animusphere. Preservation of History.

Swords. Noble Phantasms.

He was Emiya Shirou Emiya Shirou Emiya Shirou Emiya Shirou.

"What did you do to me?" Shirou grunted, his voice in a somewhat oddly higher pitch

"Well you have boobs now, for one." Zelretch gestured his hand over his chest and made grabbing motions.

Shirou mimicked the magician, and to his horror, when he reached up to grope his chest, his hand felt the distinct softness a female breast. And to make things worse, he could no longer feel the 'bone of his sword'.

"Now, have fun!" the vampire gave a thumbs up as he opened a portal behind the red head, before lightly punting her in.

Shirou Emiya made strangled screams as she fell into the abyss of space time.

Meanwhile, Archer watched in morbid fascination as the events unfolded, before getting an overwhelming urge to take a nap.

"Dumbass." he muttered

"What are you sitting there for?" Zelretch asked the servant, "You're going as well."

And much to his displeasure, Archer was kicked in too.

I don't really have a great understanding of what the black void thing was in UBW. To my knowledge, it was an aftereffect to get rid of Gilgamesh after Rin and Saber destroyed the grail. If I got the whole thing premise of it wrong, you'll have to forgive me.

By the way, I know the protagonists are not actually Shirou and Rin, just based off them, but I just wanted to explore the idea of 'what if they were?'.

Also I want me a beta. PM if you're interested.