Fate/kaleid liner PRISMA☆ILLYA
Kiritsugu killed the Einzbern family.They aren't just depowered in this Alternate Universe, according to Irisviel when Kuro asks if she could go join them, they're gone. In the original Fate/stay night verse, they were strong enough to hide Iris and Illya and keep Kiritsugu completely away; while lying to Illya about Kiritsugu. In this universe; they didn't have the same power but they still threatened Kiritsugu's family. ....this was a bad idea. He and Iris stay away from Illya to prevent fallout from other mage families affecting her.
Sudden drops in magic power are partially because of Zeltrech's Gem SwordFrom time to time, characters comment on how a magical attack isn't nearly as strong as it was a few panels ago. This is because Zeltrech's Gem Sword, which drains mana from its alternates in other universes is doing its thing in Another Dimension. Kaleido Ruby and Kaleido Sapphire being components, and having no problems at all firing gobs and gobs of mana are prime targets.
The series is set after a successful Holy Grail WarOne where Illya got her wish. In the Illya route in which this occurs, the only survivors were Shirou and Illya herself; Illya, wishing them both to be happy, created a new universe where everybody didn't have horrible backstories, and all the dead people, well, weren't dead. The new universe contained many of the concepts of the old, in new forms. In the process, she sealed away both her and Shirou's memories, and entrusted their guardianship to her creepy maids.
Black Illya is to Illya as Archer is to ShirouShe came from the future where Illya is able to fully utilize the power mentioned by Sella to be sealed inside her 10 years ago. It causes problems for her in her future and she somehow dies in a fashion similar to aforementioned hero with a tragedy to boot. She was then summoned by the Archer card as a Heroic Spirit and tries to kill Illya and stop the tragedy from happening. She also came to love Miyu, thus her lack of embarrassment from kissing Miyu to drain her mana,
Black Illyais actually the Illya from the doujin Sword Dancers I mean, look at the resemblance!
Heroic Spirit EMIYA will show upBecause this storyline needs more GAR.
Miyu is a magical copy of Shirou's biological sister and HomunculiAfter Kaleidoscope Ruby sought out Illya; Luvia Edelfelt realized that Kaleidoscope Sapphire was going to do the same thing. Instead of just finding out who it picked and bullying them; she got a little proactive. She created a being with the aspects that Sapphire would most be attracted to; and programmed her to obey her. The person she based the Homunculus on was randomly one of the people who died in the fire that made Shirou an orphan. When she realized just who she copied; she told Miyu not to tell Shirou. Shirou has amnesia of his life before the fire; and this was the age his sister was when she died.
Illya was the vessel for the Fourth Grail War.For some reason, the souls of the defeated servants was transferred to Illya instead of Irie, and she become the vessel. Thankfully, Kiritsugu managed to kill Kotomine after the great fire, win the war and had the Mage Association save the barely alive Illya and dismantle the Grail. Unfortunately, remnants of the grail and its corruption still reside in Illya, so her parents search for a permanent solution across the world, leaving her under the care of her Homonculi maids and a survivor of the great fire that they had just adopted.
Illya was to serve the same function as Justeaze Lizrich von EinzbernJusteaze Lizrich von Einzbern became the core of the Greater Grail the Key to the Ritual, Heavens Feel. Irisviel revealed to Illya she was to be the Key to the Ritual. Caren Hortensia said the Holy Grail meaning the Lesser Grail sleeps inside Mount Enzou. The cave inside Mt. Enzou is the location of the Greater Grail in FSN. The Greater Grail is the wish granting machine connected to Akasha. But since the Holy Grail War occurred only once then the container of the Holy Grail should be cup like the first to third Fuyuki Holy Grail War. Only in the Fourth Fuyuki Grail War did the Einzbern first use a Homunculus as a mobile container. Illya's and Kuro's wish granting power is the result of being partly the core of Greater Grail. This does give Illya access to Akasha thus much of her Mana is the result of her possessing Third Magic. Kiritsugu and Irisviel rebelled against the Einzbern as they do not want to lose their daughter. Thus Illya was not sacrificed the same way Justeaze was to the Greater Grail.
Black Illya is the same Illya Archer knew during his life time.We know that Illya died a year after the war in Archer's time, but perhaps Shirou tried to save her life by transffering some his power to her. This caused her to begin exhibiting powerful projection abilities and her skin turned darker (like what later happened to EMIYA). At some time before she died she used these abilities to do something incredibly badass that ended up netting her a place in the Throne of Heroes until she some how got dragged into this reality. This of course means that if Heroic Spirit Emiya shows up later in accordance with the above we can be expecting a a very touching reunion.
Sakura will play a role in the third story-arc.Sakura will show up as a Dark Magical Girl rival to the heroes a la Fate Testarossa, and she will have her shadow powers and obscene healing factor. She will eventually get "befriended" by Illya, will become a permananent resident of Shirou's harem, and the people who manipulated and tortured her into doing what she did will get their comeuppance. A possible Kaleid Liner Prism Illya 3rei! in a nutshell.
Matou Zouken created the cards.In the classic Fate timeline, he is the one that created all of the servant-binding spells, including the class system. So it makes sense that he made the class cards in this one. This could be relevant if combined with the above theory, as Matou Sakura might be able to use the cards in some special twisted way.
Miyu's brother is the Big BadMajor spoilers for the end of 2wei. There are heavy implications that Miyu's brother is someone very similar to Shirou. And with revelation that Miyu is from an parallel world, it is possible her brother IS (an alternative) Shirou Therefore it is possible that Miyu's brother is the Shirou who wants everyone to be happy. So 'his last wish' to Miyu for her to escape to another world where she can be happy and not suffering, is actually a Gambit Roulette like Fei Wong Reed that Miyu travel to another world and learns happiness and then he will use her experience with happiness and her role as a Holy Grail Vessel to wish for EVERYONE to be happy! After all, in Carnival Phantasm, the preview to 2nd season of Phantasmoon hints of Shirou as the Big Bad, it was actually foreshadowing to Prisma Illya.
Rin and Luvia being chosen to wield the Kaleidosticks in the beginning was Zeltrech being a TrollWho in their right mind would think those two would be able to work together? In what universe is that even possible. So why did he do it? Well, this troper has heard Zeltrech is pretty awesome, so I figure he somehow knew that better candidates would be living in Fuyuki, and sent them there knowing that the Sticks would eventually ditch them. He then sits back and watches the two screw around and gets some laughs in the process.
Rin's parents don't know she is in Japan cause she doesn't want them tooSeeing that there is no Grail war, Tokiomi and Aoi should be alive and well. Sakura also doesn't seem to be Rin's sister here either. Rin comes from a fairly wealthy Mage family so why is she willing to work for Luvia who she hates? Rin dislikes the spoiled rotten attention she gets from her parents being thier only child. However either Aoi or Tokiomi will catch wind that thier precious daughter is working as a maid for one of thier biggest rivals... Hilarity ensues!
Rin, Sakura and Illya will all get a big damn Heroes rescue by thier appropriate Father figure!Rin will be saved by her Dad, Sakura by Kariya, and Woe to the poor fool who tries to take Kiritsugu's baby girl!
Parallel World Shirou will teach Kuro Unlimited Blade WorksNow that they've been sent to an alternate dimension in Drei, some things are going to be different. IF this world's Shirou is alive, then he may be able to show Kuro the true abilities of the hero EMIYA. She'll also probably have her own custom invocation related to her existence and/or The Power of Friendship.
Parallel World Shirou is a loliconBecause hell, it might be true.
Parallel World Shirou is a womanizerFollowing that the parallel world is a reflection of Illya's world, the blind and dense Shirou would be one hell of a Casanova
Shirou isn't as unaware of magic as he lets onIt's just that Kiritsugu has told him to keep it a secret from everybody. After all, Shirou is the eldest child in a mage family, so it's plausible that he'd actually have learned at least that magic exists from his father.
Beatrice's Beserker install power is ThorBeatrice's install formed gave her a massive Hammer which is Mjonir, She is able to increase the size of her limbs, Thor had to shapeshift so he could be with his giantess lover, and when She and the Other girl appeared A Bolt of lightning took the group down but the other girl didn't have a spirit installed since she turns into a female Gilgamesh upon landing!
All the Ainsworth servant cards will be Heroic Spirits that would be broken by all other Grail war standardsLet's see Ainsworth Archer was Gilgamesh. Ainsworth Berserker is Thor. Karna is the most likely pick for Ainsworth Lancer. Sun Wukong would be a good guess for Ainsworth Rider due to his unique way of traveling, Cloud walking. Leaving only, The Saber, Assassin and Caster classes without a real guess.
Being corrupted through the Class Card shook Gilgamesh up more than he let's on.Not even the Corrupted Holy Grail was able to turn him mindless. This combined with Angelica taking half of his prided treasury; he's actually feeling...vulnerable. He doesn't like it. He'll never SHOW this though.
Shirou IS the Archer Card.Shirou sent HIMSELF alongside Miyu as the Archer Card. This is why there are two Archer cards and is why Shirou, apparently strong enough to hold off the Ainsworths and send her into another world (the same scale of power as the Second Magic), is reduced to (seemingly) normal in their prison. This may also be the reason why Illya was separated from Kuro when entering the alternate world, to prevent Kuro and Shirou meeting during the Ainsworth infiltration arc. When Kuro and Shirou meet, he'll eventually take his power back to become EMIYA and rescue his sister with everyone's help.
Darius is using Miyu's Holy Grail function to change history; giving power to the Ainsworth family.Which is why the Ainsworth's aren't heard of in any other dimension. This is also includes things like making Day Old Legend Noble Phantasms that not even Gilgamesh has heard of; as well as making Thor a "historical" (and probably related to the Ainsworths) figure as well as a Norse god; thus making his power accessible to Class Cards.
Miyu's world is either an earlier past of Notes or Fate/Extra or Tsuki no SangoIn chaper 17 it is revealed the true goal of the Ainsworth is to used the grail to save the world. Like the world of Notes and Fate/Extra the world is dying. There is a severe mana depletion also animals and plants are dying like in Notes and Fate/Extra. The Earth like in Fate/Extra and Tsuki no Sango is out of axis. There is a shift in the poles.
Parallel Shirou was the wielder of the EMIYA!Archer cardThe previous user of the Archer card was stated to be a sniper. As evidenced by Extra!Archer, there's been at least one Parallel Shirou that's a sniper. Plus, soul contamination would explain why Parallel!Shirou has some traits of EMIYA.
Irisviel is trying to set up Shirou with Illya and/or SellaHaving tasted Shirou's amazing cooking, Irisviel does not want to lose the constant availability of EX-rank flavors. Therefore she is trying to set up Shirou with either his adoptive sister or Sella so he remains in the household. That's part of the reason Irisviel modified a board-game to get Sella (and Leysritt) into revealing maid costumes.
Miyu is the daughter of Kiritsugu and MaiyaShe has the jaded personality that they both share (although that might just be a product of living in her crappy world), it would fit with why she considers Parallel Shirou her brother, and she sort of looks like a child of theirs might look. Possibly Kiritsugu was preparing her as the Grail as part of his plan in whatever analogue Miyu's world had to the Grail War, seeing as how the Einzberns seem to be missing or at least uninvolved with Kiritsugu there. When he learned it wouldn't work because of Avenger, he left instructions to Shirou to get her out of there.
Tanaka is a puppet made by the Aozaki sistersTokou's puppet bodies are virtually indistinguishable from human bodies, and Aoko has a magic circuit capable of harnessing tremendous amounts of power. She is also able to make things indestructible.