This is an idea that would not stop bugging me. There have been crossovers for this section before but they have all been abandoned without completion, series of one-shots or so complex I still don't understand the whole thing through on my third read, A Different Path, 'cough cough'. Others are good but are the inverse of the above stories, Shirou and company entering SAO rather than the servants being Players of SAO. And yes I do plan to have every Servant summoned in the fifth war originate in Aincrad. I will pull from the Anime only as I want to avoid using references to the Alicization light novel or the web novel that is no longer the true canon with the light novel replacing it. This will be my first written fic, other ideas I've had before not being written down or captivating me enough to put pen to paper. Any ideas for improvement would be helpful as a review and although I believe I know both canons well enough here if I slip something up please leave a review telling me what it was and I'll endeavor to fix it.
With that out of the way.
Kischur Zelretch Schweinorg was growing bored again. If the magus association at large discovered this many would begin to panic, perhaps even fleeing. However he held next to no interest in them at this point, petty pranks utilizing the second true magic had grown dull at the moment, perhaps another time but today they would not entertain him. And that was the issue with immortality it grew dull after a long enough time. He considered peeking into one of the many Grail Wars occurring throughout the infinite worlds, but after seeing so many of them the similarities began to blend through far too much. All appeared to alike for a 'natural' one to amuse him. But if entertainment good enough for the Wizard Marshall did not yet exist, he merely had to create it.
Not an entirely new Grail War of course, that would take far too long even with the powers of the kaleidoscope. No he simply had to alter an existing one. Change a few catalysts to suit his needs and he'd have some perfect entertainment to cure his boredom. But locating seven catalysts that he could toss about would be difficult, even three or four would be a challenge. The kaleidoscope had rules that even he had to obey, if only so he didn't break anything too important with his machinations. Seven may not be doable, but he could always try using one catalyst for summoning all the Servants. It would make the battles all the more entertaining.
Hmm, ah this should do! Zelretch pulled allowing a relatively small amount of his prana to flow into the word, the worlds, drawing forth a silver metallic helmet, cushioned on the inside with a small black chinstrap, seemingly velcro, and and a transparent glass visor. Now, where to put to ensure it was used. Inside the grail should do finely, and it would have the added benefit of rousting that cursed Servant, or was it Servant of curses. It made little difference, it would be sure to be thrilling all the same.
Angra Mainyu felt something shift, a foreign object entered the grail. But how? The Grail is a vessel for prana and naught else should be capable of entering. Oh, what is this? A catalyst? Angra Mainyu could use that. It, for the embodiment of all worlds evil did not truly belong to either gender only appearing as if it did, could, would, use this a form of control over the Servants summoned beyond the vague sense he could receive from the Grail itself. Perhaps not outright deciding what Servants would be called forth, but perhaps a change of class or nudging the Grail towards one Servant and away from another when the factors involved were not truly decisive. Yes with this helmet Angra Mainyu was that much closer to unleashing all the curses he could muster unto humanity.
Illyasviel von Einzbern was ready to summon her servant. It mattered not that the Heaven's Feel Ritual would not begin for another two months, she had been birthed with a prana capacity far exceeding a normal magus, and it had only been enhanced with the modifications that Jubstacheit, or Grandfather had made to her after her father had betrayed the Einzberns in the Fourth war. She could handle supporting one servant for those two months, and it would give her many advantages over her future foes in the war. She would know her Servant and his skills stats and Noble Phantasms far better than any other Master would know their Servant. It would allow time to plan based around her servant as opposed to other master who knew not the abilities of their partners till the war truly begins, two months from now. So she began. Calling forth her Servant, Heracles it would be, as determined by the slab of rock extracted from his tomb. He would be her Servant her Weapon, her Protector. She felt it the large drain on her reserves and then opened her eyes to see-
"You're not Heracles."
Thanks for reading. Please leave a review a review on how you thought the prologue was. Does my setup for the story seem plausible? Any guesses on the identities of the Servants who will be summoned? Any feedback is welcome and appreciated. Keep in mind this is my first fic so try not to be too harsh.