Author's Note:
The beginning of Fate/Crystal Cross takes place roughly 15 years after the canonical end to Fate/Stay Night (i.e., the True End of Heaven's Feel in the visual novel). Spoilers for this route are included in the text. In later chapters, you can also expect spoilers for Inuyasha, Magical Girl Lyrical Nanoha (StrikerS), Buso Renkin, Gurren Lagann, Death Note, Dragon Ball Z, and Slayers.
The idea behind this fan fiction was to bring some of the most powerful characters in popular anime series together in a reasonable way (and yes, I am aware that "reasonable" is a relative term and not terribly appropriate for this big of a crossover). Employing the Second Magic of the Nasuverse (the universe that includes the Fate series) enabled me to give at least some excuse to try this idea out. I appreciate anyone who's willing to swallow the explanation and join me on this crossover adventure, and hope you enjoy it.
Prologue: One Year Ago
Rin Tohsaka found him praying alone in a room she well remembered. He was burning incense sticks, and their cloying scent permeated the air. The incense burned in front of a photograph of a young girl with red eyes and snow-white hair. Ilyasviel von Einzbern's last months had been happy ones, in spite of all the hardships that came before and the fading away at the end. Even Rin remembered her fondly.
Quietly, she slid the door closed behind her and went to kneel next to Shirou. He didn't react to her presence at first, and so she took a moment to examine him.
In spite of his artificial body, he had aged just like she had; like they all had. He was still in his mid thirties, but she saw a few strands of grey in his hair. What hadn't changed lay in the intensity of his concentration, his furrowed brow, and his slight frown as he prayed intently.
Smiling, Rin turned to Ilya's picture and closed her eyes as well. She didn't think of Ilya, but instead reflected on all the things that had happened since the last time she visited Fuyuki, and since she had left to study with Zeltretch after the War… it felt strange to be here again. When had she last visited? It must have been at least six years ago. She hadn't visited more than twice before this. Perhaps she'd visited only once. Perhaps it wasn't six years since she'd been here, but longer.
"I thought you were Sakura."
Rin opened her eyes and looked at Shirou carefully. Now he was smiling, and that particular smile—so pure and optimistic—made her chest ache. It was an ache she would never acknowledge, but an ache nevertheless.
"Sakura's already in the kitchen," she replied. "She hardly even gave me the chance to say hello before insisting on making tea." Rin ran her fingers through her hair. It was a habit she'd never gotten out of.
Shirou laughed good-naturedly and stood up, extending a hand down to her. "Then we shouldn't keep her waiting."
"I suppose so." Rin took the proffered hand and accepted Shirou's assistance in returning to her feet. "It's good to see you."
When they returned to the living room for tea, she was greeted by the familiar purple-haired Rider. This was someone who had not physically changed. If not for Rider's strong magical presence and the square pupils that hid behind her glasses, it would be difficult to regard her as the powerful Servant she really was. Sakura soon came from the kitchen with a pot of tea freshly brewed, and they all sat down to exchange stories and catch up with recent, trivial happenings. Rin had sworn secrecy about her work with the Second Magic, so she let Shirou and Sakura provide the majority of the conversation while she and Rider listened politely. There was talk of a possible adoption, of changes in the town, of television programs, of newly perfected recipes. And so the afternoon passed pleasantly, and Rin had to give little more than appropriate commentary and an assurance that yes, she would be staying for the night.
As it turned out, that night in another world, another Rin Tohsaka made a mistake that hundreds of thousands of Rins in hundreds of thousands of worlds had made before her: she tested a new blade to open a rift between parallel worlds. The single slash of that blade was one cut too many, and this time the rift didn't entirely close. The Rin visiting Shirou in Fuyuki could not have noticed the small amount of mana leaking into her world from another, nor could she have suspected that the outflow would only grow worse and bring in more, unsavory complications later.
