Disclaimer: I do not own Rising of the Shield Hero or Fate/Stay Night.
It had been a normal day. Emiya Shirou had woken up, gone to work, practiced magecraft with his girlfriend Tohsaka Rin, and gone to the library.
… Admittedly, to those unaware of the Moonlight World, one of those actions would have seemed out of the world.
Regardless, he was in the library when things started to go awry.
A voice rang out as books fell. "What the hell, man?"
Despite his battle with his own future self, Shirou still found himself unable to deny someone who was clearly in need of assistance, no matter how minor the matter may be.
Walking quickly to the other, he bumped into the black-haired man. "Sorry!" He cried. "Do you need help wi—" Shirou was cut off.
It felt as though he had just hit his head on stone.
"Ugh." He proclaimed, more out of habit than actual need— he had gotten plenty of practice with applying [Reinforcement] instinctually during the catastrophe known as the Fifth Holy Grail War or Heaven's Feel.
Becoming fully conscious once more, no longer slave to his battle instincts, Shirou noticed the hot weight of a body next to him with the cold feeling of steel and chose to embrace said instincts once more.
The air, it's rich with mana. Shirou realized.
Jumping to his feet once more, he temporarily shelved the idea of asking aloud his questions to the only party he could notice in his line of sight, instead instinctively using [Tracing] to use [Structural Analysis] on the other's shield.
ErRor: STrucTure is foReIgn To uNlimIted BlAde woRkS
But even before he could read the history of the shield, he was blocked by one of its properties and a splitting headache.
Shirou had only ever encountered one weapon that also blocked off his ability to replicate it: Gilgamesh's Ea.
… But based on his debriefings of the Holy Grail War with Rin, he had an idea. The weapon itself could be foreign to both himself and the World, just like Ea was, predating the concept of [Weapon].
And wasn't that a scary thought— that some random man, or at least Shirou assumed a man, had access to a weapon like that.
Another voice rang out, drawing Shirou's attention to the center of the room. There were many more people there than the singular other person he had originally thought.
"Oh, honorable Heroes! Please, save our world!"
"Huh?" Four of the people asked as one. Shirou was inclined to join them but he was prepared for battle.
Talking, or really any extraneous usage of breath, was a sin in battle, after all.
Though, I'm not in battle at the moment.
"Huh?" he added, mere moments after the others spoke.
Looking around him, Shirou noticed that the people in robes looking more decorative than practical were frowning and looking with disgust at the person with the shield.
But before he could do much, one of them spoke once more. "You must have many questions, but time is short. You are the chosen Heroes, summoned here by an ancient ritual."
"Summoned?" the man with the shield Shirou couldn't analyze asked.
Now that I look at him, I remember him from the library. Ancient ritual summoning heroes? That's more familiar to me. He smiled grimly.
Looking around, Shirou noticed that the objects of focus, the people holding onto weapons, weren't paying attention at all. The only one who seemed moderately interested in what was happening seemed to already have been declared Public Enemy Number One.
"Currently, this world is teetering on the edge of destruction. We pray of you, please, lend us your power!"
"Man, so much talking."
"This sucks."
"Right?"
It seemed as though the others were of the opinion that the world they were pulled into was a fake.
Shirou had enough knowledge and experience with summoning rituals to know otherwise.
His girlfriend's own mentor in magecraft was Zelretch after all.
Though while he was the only practitioner of the Second Magic native to Shirou's own dimension, it did not mean he was the only user in all dimensions.
…All the same, I doubt a true master of the Kaleidoscope would need the help of others in battle, especially those that don't seem to know anything…
Suddenly, one of the others summoned began to examine his sword methodically.
Still, the teenager kept fumbling with it, almost nicking his hand at multiple points.
"Even if you send us home when the job is done, that's basically just using us as slave labor, you know? You get where we're coming from, right? Keep in mind that depending on your answer we might have to become your enemies."
"Ha"
He couldn't help but let out a slight chuckle.
That guy, he doesn't seem to realize his situation. Summoned to a new dimension without any skills— what is a person to do except not anger the person who summoned them.
Even so… I can sympathize with them.
One of the men in robes spoke up, glancing nervously at the sword. "P-Please, at least have an audience with the king before you do anything rash. You can discuss the details of your compensation there." Muttering, he continued "Yes, yes that'll do" to another robed figure who was opening a great door.
Walking with apparent purpose, the three people with stereotypical weapons moved forwards. Shirou tagged along behind them alongside the man with a shield.
a/n
It's been a while since I've uploaded. This story is one I'm writing purely for fun as I'm stuck with what to write for my rewrite of Fate/Hero Academy. I've gotten into watching Shield Hero and reading some of it as well. Some of you may have noticed that I lifted lines of dialogue from the web novel. That is something I don't intend to continue doing but at the moment there haven't really been changes to the timeline— so I need to introduce Shirou a bit more to do so.
Of course, this is a Shield Hero F/SN UBW crossover, so each side might be a bit, well, OP by the end of the story.