[Ithekro]

Well...she's presented at first like a Mary Sue. Miya is way more intelligent than her classmates. She's faster than Illya (the present fastest in track), and has better cooking skills than maybe even Shirou. But even so...logic suggests she has an origin someplace.

Shirou is still adopted by Kiritsugu in this world. I don't think they give a time for him to be adopted. Nor do we know what happened to his family in this timeline.

We know Ruby takes a blood sample, physical contact, and a full name to make a contract. Than opens up alternate realities to make Illya a magical girl. Sapphire, as far as I remember, doesn't go into detail about how she found Miya, nor does Miya talk about it in particular (that I recall).

Miya appears for the first time at Illya's school the day after she appears the first time as a magical girl in front of Illya (capturing the "Rider" card). Illya thinks it is too predictible....Illya watches too much magaical girl anime. Therefore, even though Miya is Illya's age, she was not enrolled in Illya's school until after she became a magical girl. She was probably also in Japan at the time since that is where Luvia and Sapphire had a falling out. Sapphire seems much more willing to talk about stuff than Ruby, but they both seems to keep stuff from others. Is there a chance they used Illya's blood to summon another verson of her and implant that on say, a cat, to create a familiar? But Miya doesn't seem to have the power of the grail inside her like Illya seems to still have. It is a mess.

So far we have, same birthday as Illya. Thinks Shirou looks like her brother. She was overseas at somepoint. Her father died and her brother went away.

That points, oddly, to her being Illya. Aside from the same birthday, Illya in Fate/Stay Night...Shirou is adapted and becomes her brother. She goes overseas to live in Europe. Her father dies. She comes back to Japan. It was just the three of them since Irisviel was dead by then.

It is just a matter of timing. I don't know the details of when or how Kiritsugu left Illya (the why I assume had something to do with Irisviel and the war) and took Shirou with him. I know Kiritsugu died about five years before Fate/Stay Night and Shirou was alone....or rather in Taiga's care. Illya was with the Einzberns and I guess would have had issues with Shirou for taking daddy away. But if Miya is a version of this Illya...why does she look different...and why is she so cold. Even F/SN Illya smiled a lot. That is why I'm thinking familiar...probably because of seeing Len in Carnival Phantasm...the "emotionless" familiar.

But we are still in the dark I guess.

"Accident" meaning something that wasn't suppose to happen. Kuro would be a "miracle" because she's basically an unbound servant/clone I suppose. Miya might be something like that as well, but with Sapphire she's had unlimited Prana...so she's here to stay...were Kuro could vanish. So it isn't a "miracle" that Miya is still around...just an "accident". At least I think that is how it works?

But that too is likely grasping at straws...so to speak.