XANA is NyxThe monsters are Shadows, William is Takaya, Ulrich is Akihiko, Odd is Junpei, Yumi is either Yukari or Mitsuru, Jeremy is the MC, and Aelita is Aigis. The Lyoko forms are Personas (who seem to only know Physical skills) and the scanners are Evokers.
XANA is Franz Hopper.Fan-theorising on Lyoko Freak has suggested that Franz Hopper created XANA's AI using his own brain-waves. The catch? Once Franz was dead, how does the supercalculator tell the difference?. Also, it's at least heavily implied by Franz's journal entries that by the end he was a couple of sandwiches short of a picnic; an insane human mind is likely the last thing you want to try to model as a computer program, even on the world's most Badass Quantum Computer. It's entirely possible that a combination of this insanity, simple data corruption and the inherent instability of a Multiple Agent System (like the Marabounta, which didn't even have an AI and still went badly wrong) caused Franz to either merge with XANA or replace him outright. Result: Instant lunatic, just add water. The result is either some strange form of Split Personality or a Gambit Roulette that has yet to see frutition. Or both. There is some evidence for this:
XANA is Antea Hopper.A variation on the above, for those who think Franz wasn't several sandwiches short of a picnic. In this case, Antea was kidnapped sometime during Franz's last days on Project Carthage. In disgust, he leaves the project and uses its resources secretly to rescue his wife. Trouble is, the MIB have turned her into an AI construct. Counter-theories to the above bullet points follow:
The story is the final chapter of the .hack saga, .hack/LYOKOSometime after the current .hack series, the World is pulled offline permanently. It turns out that Jun Bansyoya's journal lied, and Harold Hoerwick returns from years of study into molecular manipulation to gather up the remaining The World computers and reconfigures their data into a new version on a quantum computer, creating Lyoko. He then retools Aura into a more realistic version, Aelita, and prepares to finally bring her into the real world as a testament to his love for Emma. He even goes as far to create a fake identity, papers, and photos, so that he and the new Aura will look like a convincing family and be able to hide from CC Corp. Something goes horribly wrong, though, and Morganna remanifests from the hidden depths of the New World as XANA.
Code Lyoko takes place in the Marvel Universe.C'mon, Marvel bankrolling the short-lived Code Lyoko toyline and MoonScoop producing a short-lived Fantastic Four animated series? It can't be a short-lived coincidence. Now that XANA's gone, our heroes will move to England, become the Ultimates X-Calibur team, and work in at least three Doctor Who references a year.
The Supercomputer has enough power to determine The Ultimate Question Of Life The Universe And Everything.In a rare occurence of reaching through the other side of the Fourth Wall Mail Slot, it's "How long will CL fans have to wait, in years, before the entirety of Code Lyoko comes out on Region 1 DVD with French audio?" the end of the Multiverse as we know it. Thus, the Men In Black needed to ensure a Stable Time Loop by forcing him to shuffle off the mortal coil, through death or other means. Since death would throw a wrench into future events, they chose "other means" - if Franz and Aelita didn't evacuate to Lyoko of their own accord, they'd drag them into the scanners. Kidnapping Antea (and possibly turning her into XANA or a XANA-prototype as denoted above) was insurance to make sure Franz would continue his work on a virtual world derived from Project Carthage and eventually take up permanent (or at least permanently disembodied) residence in the end product.
Aelita learned how to use Energy Fields in the Time Skip between Seasons 2 and 3 by marathoning Naruto.Alternatively, she knows Jump Super/Ultimate Stars.
Harold Hoerwick was on the Project Carthage staff.Largely a concession to the ".hack//LYOKO" theory above. Other notable scientists include:
XANA's name is actually "Xana".When Franz Hopper created the super computer he designed it to use a case-insensitive character encoding to get a (very) small boost in performance. Hence why everything, including XANA's name, appears in all caps.
XANA is a prototype of the Hunter-Seeker Algorithm.Formless in its structure, horrifyingly versatile in its offense, XANA's activities fit the Hunter-Seeker's FMV to the letter.
Franz Hopper isn't Harold HoerwickAlthough Franz and Harold had the necessary knowledge to accomplish their goals separately (destroying Carthage and materializing Aura respectively) neither had the necessary resources so they decided to work together to accomplish their goals. However, Harold was kidnapped and tortured for information by the Men in Black, he eventually committed suicide, but not before revealing he was working with Franz. The Men in Black then kidnapped Antea hoping to use her as a hostage in order to force Franz to work for them. In order to ensure she wouldn't escape or kill herself they virtualized her using an older model scanner. However, she managed to escape onto the network and eventually made her way to the super computer where she became merged with Morganna and they become XANA. Furthermore, when Aelita Schaeffer was virtualized onto Lyoko, XANA merged her data with Aura's (creating Aelita Stones) in order to both protect her and prevent Aura's materialization.
XANA was made with Progenitor technology.Yes, yet another SMAC-themed WMG, I know, but bear with me.
XANA turned William into an Espada.Jeremy provided the BFS, all XANA had to do was write all the jokes at Ichigo's expense. And possibly Chad's, with all the times William wound up getting Worfed.
Franz Hopper survived. AGAIN.Admit it, the guy never seems to die when he makes a Heroic Sacrifice, and whenever he shows up afterwards, it's always a good thing he could heal. This means, of course, that he'll turn back up eventually, but it'll take something as drastic as Un Monde Sans Paix to necessitate it.
Why does the dub deny any personal attachment to Paris?Simple: Lyoko or some analogue actually exists, and the MIB aren't all that keen on admitting the French beat Area 51 to it. The lack of editing on MoonScoop's part, by association, is a subversive measure to break the Masquerade, spearheaded by none other than Sharon Mann herself. And possibly himself.
Aelita could come into some massive alimony payments should she choose to forgo her Undead Tax Exemption.Let's see, that's 10 years of data stasis and emotional damages thereof, plus child support from Franz (because he's STILL ALIVE, as noted above), multiplied by punitive damages to be assessed against the Men in Black, minus a rod of U-235... I think I'll just toss her this catalog of Upper West Side apartments and she and Jeremy can call me back when they find something good.
Sissi is a clone.Blame Carth for semantically introducing the possibility that Sissi might not have (or have had) a mother. Then again, tossing a cheerleading baton into the air, never to return, isn't something that can be easily done with natural human strength. (Technically, she did it twice, but I (you should know the one by now) am using "XANA Awakens: Part 2" as my frame of reference because XANA wasn't mucking with the Earth's gravity that day.)
Taelia is Aelita's half-sister.Antea Hopper is still alive. She escaped the custody of her kidnappers after some 5 years thanks to the help of one of The Men in Black who fell in love with her and betrayed his cause. Believing for a while that her husband and Aelita were dead, she started a new life on the run with her savior. A girl was born some 2 years later, and Antea gave her a Significant Anagram name of her lost daughter: Taelia. The father discovered some years later, from a lasting Men in Black acquaintance, that Waldo Schaeffer survived but was almost captured again, and then disappeared for good. Antea still wanted to find him and Aelita, but doing thorough researches was difficult and risky. After many years, they uncovered his last whereabouts: he had lived under the name Franz Hopper and had been teaching at Kadic Academy. To not attract the attention of any potential Men in Black surveillance, Taelia was enrolled for a short while so that she could glean some information about Franz Hopper by peering through the school files or discreetly interrogating the principal. She pretended being an orphan to deflect any question about her parents. What? That makes a LOT more sense than the Identical Stranger scenario...
Project Carthage (though not necessarily Lyoko or XANA) was originally a time-travel project.Instead of Carthage being a tactical reference, it was their goal. They could already travel forward in time, by uploading themselves and then having the programming frozen from the outside, rematerializing once the physical computer reached the intended destination, having travelled at the speed of 1 second per second. They did not, however, have any idea what they were doing trying to go into the past. The 24 hour limit was either a result of Jeremie's inability to unlock it any further, things went haywire if they went too far back, they decided it wouldn't be worth going back in time too far since anyone who died in the interval would still be dead, or, this troper's favorite, nothing exists more than 24 hours before the present.
Code Lyoko and Oban Star-Racers take place in the same worldNot only do they share at least one creator (Thomas Romain), but a motif of facial tattoos is present in both series. Odd has several on his face in his CGI Lyoko Warrior form, and in hers, Aelita has two thick vertical lines on her cheeks, similar to the ones Molly and Maya have on Ōban Star-Racers. Coincidence? This troper thinks otherwise.
Jeremie wasn't the first person to find the super calculator after Franz Hopper and Aelita were trapped on Lyoko.The people who originally found it they also tried to materialize Aelita, but instead only succeeded in creating imperfect infant copies of her, which they adopted and named Jeremie and Taelia. At some later point one of XANA's attacks proved fatal and the decision was made to shut down the super calculator (quite possibly by Aelita herself).
Odd and Love Momozono are related. More likely cousins.Both are blonde, both are lively and chirpy, and Love acted like a cat in episodes 14 and 15 of FPC, while Odd's Lyoko avatar just happens to be a kitty-boy. The reason for them having different surnames was that Ayumi (Love's mother) and Odd's father were siblings, and once Ayumi married Kentarou (Love's dad), she took on his own surname. Similarly, William and Setsuna/Eas seem to have connections: both have black hair and had an evil phase, but in reverse directions: William was good and he became evil, and Setsuna started out evil and became Cure Passion.
Odd's affinity for purple and his flirty attitude might be caused by the excessive number of females in his family.Seriously, having a mother, five sisters, and (referring to the Love theory above) a female cousin (no, Aelita does not count since she was pretending) might just influence him. And make him want more.
The World is a SimulationThe "Real World" is actually a simulation like the Matrix (or is the Matrix), and Lyoko is a simulation inside of a simulation, or perhaps, a different layer of the same one. This would explain XANA's ability to seemingly violate the laws of physics. It also explains the Return to the Past: a type of loading of a saved state (or backup as it may be), but those excepted from it overwrite their old selves. Could also be why Jeremy's hacking is so effective at things which would seem to have other checks and balances (like Aelita's identity).
Aelita's personality completely changed when and because Franz Hopper restored her memories.The Aelita in Seasons 1 and 2 and the Aelita in Seasons 3 and 4 are two completely different Aelitas, because a new Aelita was created when Franz Hopper gave her memories back. As a blank slate on Lyoko, Aelita was probably closer to the definition of an artificial intelligence- or maybe simply an amnesiac. She shows marked traits- an overactive martyrdom instinct, a demure, naive personality (though this does evolve slightly due to outside sources), and, for the little time she knows about her parentage before the memory restoration, acute hatred of her father. My best guess is that when Franz Hopper restored her memories, he also restored a bit of her previous personality, and maybe a bit more humanity. She becomes noticeably more outspoken, she takes many risks both physically and socially, the martyrdom instinct vanishes (maybe because of a renewed sense of dignity?), she receives different powers for no apparent reason (this I think is the big one- because her brain changed, the makeup of her Lyoko form changed as well. The energy balls could be symbolic of her assertiveness...or uh something.), and, big one, she absolutely adores her father. Aelita wasn't replaced, because she has memories and all, but she was definitely heavily modified.
Jeremy is Haruhi.He probably created all of Aelita's past and a way to bring her to the real world because he was really in love with her, and it'd be troublesome if she didn't come to reality, like he wanted. The change in personality was because it was how he imagined her.And XANA's Game Breaker status was just a way to keep away from the massive boredom. He probably created this new Universe after Haruhi saw that there was a game so awesome she wished it was real. Lyoko is this game.
The Men In Black aren't with the government, but with Smart Brain.Antea and Aelita are Flamingo Orphenochs, whose cellular degeneration issues were fixed by Franz using Project Carthage and/or Lyoko (an independent project to break Smart Brain's status as leading Mega Corp. by making their superhumans beholden to someone else besides the Orphenoch King for their gene fix). No word yet on how involved Decade has become in "Lyoko no sekai."
A crazy, yet plausible theory to Odd's Lyoko form.The night before he enrolled at Kadic, he read the original Alice in Wonderland book before sleeping. Then, he dreamed about Kiwi peeing on a random log, where the Chesire Cat was resting. Kiwi and the Chesire Cat then started fighting... and then Odd woke up. Hence why in Lyoko he is dressed as a purple cat with a picture of Kiwi peeing as his Chest Insignia.
Yumi grows up and becomes Yumi Azusa.She eventually moved to Death City, and somehow became a weapon and decided to enroll in the DWMA. I mean, look at her. Azusa dresses similar to Ishiyama, the hairstyles are fairly similar.. as for the last name, it could have been her mother's maiden name that she decided to take, and the reason she's called Azusa most of the time is because her father named her Yumi and she now has a grudge against her father like Maka does. She never mentions Lyoko because, well, she has to keep a secret.
XANA possesses humans because he enjoys taking human form.It's the best explanation we've got. When he first possessed a human (Sissi), he made a comment in her body that he had "never felt so good." Perhaps over the seasons, XANA developed a liking for, or even an addiction to taking human form for some reason. This is why he did so, again and again, even after it was long established that this method did not work. He took William as his slave in Season 4 in order to have a human to possess whenever he wanted.
Ulrich's real parents are Kyon and HaruhiGot the idea from a since-removed Youtube video saying that kyon and Haruhi are Ulrich's parents due to Ulrich being a slight expy of Kyon and other reasons. Haruhi just transferred the baby to the stomach of a French woman. She IS god, after all.
Jeremie is Jeff AndonutsBoth characters are very smart for their age and are great with technology, not to mention they both have a similar hairstyle, blonde and wear glasses.
Xana was never corruptedXana was doing exactly what it was programmed to do: destroy Project Carthage. In order to do that it needed to leave the factory. The program was merely protecting itself when it trapped Franz and Aelita Hopper and was continuing to protect its mission for the entire series.
Xana actually trapped them in a different bubble simulation at the end of ghost channels and they just think they are in the real world
William always was Xana and still is.
XANA is 4chan!The site has gotten self-aware and all the attacks are actually epic trolling! XANA is sitting on his throne of CP and laughing at them, thinking they destroyed him, but 4chan is still up! That means 4chANA is waiting, then will do an epic troll move and mess with their ego, by sending a giant Pedo Bear to attack them!
XANA thinks that Yumi is the strongest Lyoko WarriorIt would explain why she's XANA's Designated Victim, after all. And there's some evidence to suggest that she is the strongest, at least emotionally - being a year older, she's naturally more mature and headstrong than the others. She's also had the most experience with the supercomputer other than Jeremie and Aelita (by season 4 she can perform Returns to the Past without guidance). And her performances on Lyoko are generally impressive as well. She's managed to beat William single-handedly at least twice, and she's the only one to have defeated Aelita whilst she's under XANA's control. All that added together explains why XANA goes after her so much - he reckons that if she goes, the others will be severely demoralised, and it'll be much less difficult to put them down as well.
Hiroki is adoptedThink about it. He's nowhere to be seen in all of season 1, even on occasions where he really should have been, such as in "Holiday in the Fog" when Yumi's family were going on vacation. This is because Hiroki isn't Yumi's biological brother, but instead he was adopted by the Ishiyama family sometime between "False Start" and the beginning of season 2.
Replikas are XANA's equivalent of HorcruxesJeremie's assumption (which the show then takes for granted) is that if all of the Replikas are destroyed, XANA will die as well. However, here's a different theory - although XANA is free from the Supercomputer, he still has certain limitations based on his core programming. That means that he still needs towers to attack the real world, and so he began usurping other supercomputers to create new towers to do just that. However, in the act of usurping each supercomputer, XANA left his core programming increasingly exposed, because he'd have to siphon off some of his power to create Replikas, much like how Voldermort had to split his soul and siphon part of it into his Horcruxes. This means that destroying the Replikas wouldn't destroy XANA totally, but instead they'd leave him much more exposed to a final attack. That's how Jeremie's multi-agent program destroyed him - it targetted all of the Replikas simultaneously, and once they'd all been destroyed, the program launched a final attack on XANA itself, killing him for good. If the Replikas had simply been destroyed and the Supercomputer shut down, XANA would still 'exist', but he wouldn't be able to do anything until he usurped another supercomputer.
Code Lyoko will reset it allEvery time they use Code Lyoko, they get sent back in time. One day they might get sent back to the beggining of all creation.
William is a fan of Final Fantasy VIIWhich is why his Lyoko Avatar is based on Cloud/Zack.
Ulrich has dyslexiaUlrich is often shown doing badly on his schoolwork, frequently getting 'D-' or 'F' grades. Yet when Ulrich is with his friends and fighting XANA, does he seem unintelligent to you? My theory is that Ulrich is actually fairly intelligent - not to the same extent as Jeremie and Aelita, but still quite smart. However, because he has dyslexia, he has difficulty in reading books and writing essays, thus leading to his bad grades. The problem is that no one else has noticed that Ulrich is dyslexic, and thus slates his poor schoolwork as being down to laziness and a refusal to study. For instance, when Mrs. Hertz is chewing him out in "Nobody In Particular", he apparently wrote that a nucleus was made of "croutons" rather than "protons". Perhaps he did know the right answer, but due to his dyslexia he ended up writing a different word. Likewise, when another teacher slated his essay in "Double Trouble", the main critique was about the multiple spelling errors. Unfortunately, Ulrich is too shy and embarrassed to talk about his problems, even to his friends, so he doesn't get the help he needs. Remember how reluctant he was to admit he had vertigo? Frankly I'm surprised that it took me this long to consider this possibility...
There are multiple XANA-esque programs across the worldWhile the gang are fighting XANA from Lyoko, and eventually delving into the internet itself to destroy supercomputers that XANA has taken over, there are multiple different groups fighting rogue computer programs just like XANA all over the world. Naturally, none of these groups know that any of the other groups exist, and so continue to fight computer programs in their respective virtual worlds in countries such as the United States, Australia, United Kingdom, China etc., basically every country that has powerful computers at their disposal. In the first two seasons, shutting down the supercomputer would only have removed XANA from the picture - the other rogue computer programs would still threaten the world's safety. Franz Hopper is aware of this, and so he sent data to Jeremie about all the other self-aware computer programs that existed. Thus, in "Fight to the Finish", Jeremie's multi-agent program was so powerful that not only did it destroy XANA, but all the other computer programs as well.
Lyoko is Franz Hopper's Minecraft worldSeveral years into the future (from the show's perspective), Hopper bought Minecraft and discovered the issue of lag when using too much TNT at once. So what did he do? He built a supercomputer that would allow him to blow up as much TNT as he could ever want. After a while, he got bored and added more features to the computer, including the ability to enter a read only version of his world and, for some reason, go back in time. After getting bored with that, Hopper made several mods that, among other things, replace the mobs we all know and love with more science fictiony mobs, make the world generate differently, cause falling into the Void to be more punishing, and, due to the computer's massive amount of power, add towers that can affect the real world with the right redstone sequence. And after a while, he used the computer to take it all back in time to the 70s where he settled down, got a wife, and eventually got his daughter so addicted to Minecraft that she went into the world and refused to leave. Consider these similarities:
In Code Lyoko: Evolution, Sissi will have a Lyoko form.At the end of the first series, she became friends with the cast. Why shouldn't she, now? Also, evolution makes me think upgrade, including in character ages. If they're older, they should have become closer, so why not let her in? If she does get one, I think it will be a Zelda/Sheik type deal. The Lyoko form represents your inner desires, don't you think Sissi would totally be a princess in that form... But it has to be combat ready, making me think that it will be like Zelda and Sheik.
Franz Hopper gave XANA a virus at the end of "The Key"As we all know, at the end of "The Key" XANA managed to escape the supercomputer by stealing Aelita's memories, and Franz sacrificed himself to bring Aelita back to life. However, what wasn't shown on-screen was that while Franz was giving his daughter back her memories, he was also implanting a 'bug' inside XANA's core systems as he was escaping Lyoko. Throughout season 2, XANA maintained a link between him and Aelita so that if he died, Aelita would too. In this instance, however, Franz turned the tables on him, and the bug made it so that if Aelita died, XANA would be destroyed as well. This would explain why XANA never tried to kill Aelita throughout seasons 3 & 4, even though he's tried to kill the other Lyoko Warriors - doing so would lead to his own destruction. This also explains his actions in "Hot Shower", and indeed why he wants Aelita imprisoned within the Digital Sea - if she was trapped in the Network, then technically she'd still be 'alive', but completely unable to do anything. Thus, XANA wouldn't have to worry about the one key threat to his existence, and as soon as Franz Hopper was out of the picture, victory would be almost guaranteed.
Every episode after "Ghost Channel" never actually happenedIn "Code: Earth", Aelita is finally materialised onto Earth, and in "False Start" she spends some time on Earth before being forced back to Lyoko. Then in "New Order", Aelita lives on Earth with everyone else. Well, that's what the show tells us anyway. In fact, every episode in the series except for the first 24 is merely a hallucination on Jeremie's part. On that front, so is the scene in "Frontier" where he touches Aelita's fingertips. What really happened is that XANA succeeded in one of his attacks for once, killing many people in the process. The gang realised that they could not handle XANA any longer, and reluctantly shut down the supercomputer. Jeremie, distraught by the loss of his one true love, even if it did happen to be a computer program, went completely insane and began hallucinating that he had finally managed to materialise Aelita (hence "Code: Earth" and "False Start"). Everything else that happens afterwards consists of further hallucinations from Jeremie - Aelita being able to live on Earth full-time (Jeremie's biggest dream), the revelation that she's human (thus making Jeremie's love for her less 'pathetic') and everything else... all of that is imagined by Jeremie as he lies in his bed, his friends having long since abandoned him, and the episode "Echoes" represents Jeremie regaining his sanity and letting go of his delusions.
There are two AelitasTo be specific, the first Aelita lasts from the start of the series until the episode "Just In Time", when she's deleted. When the gang materialise the hair that was materialised, the implication is that it's the same Aelita. However, if you listen closely, you'll notice that they mention that the hair 'recreates' Aelita's code, rather than 'restoring' it. In other words, they made an exact copy of Aelita, with her memories intact. Now, at the time there wasn't much distinction, with her being assumed to be an AI and all. But this essentially means that the Aelita that went through so much Character Development, discovering her past and fighting XANA all the while, was not the real Aelita at all, but a computer-generated clone of the original Aelita.
XANA is a Knight TemplarFor all intents and purposes, the show paints XANA as a monster, whose exact motivations remain unknown throughout the four seasons. However, a very distinct possibility is the idea is that XANA is a Knight Templar who holds a very firm belief that Humans Are Bastards. During season one, the only way he sees of removing their bastard-ness is to eradicate them totally. However, after season two, his motivations change as he grows in power - now, he instead wants to become powerful enough to possess everyone on Earth, and manipulate them in a way that he believes will 'benefit' the rest of the planet. This explains the robots we see late in season 4 - perhaps they are designed to get rid of anyone who manages to resist XANA's possession. More importantly, it explains why possessing humans is by far XANA's favourite method of attack, despite the fact that it has failed to produce results multiple times - he wants to stay in practice for when he's finally strong enough to possess millions of people at once.
The Supercomputer was Sailor Pluto's PCAnd she built it herself, adding the Time Travel function and the holographic part out of boredom (she has literally nothing to do for a long time). Also, she powered it with plutonium to keep herself entertained when she had to recover the fuel. Then she grew bored with it too and hid it near Paris, where Franz Hopper found it.
Jim Morales does not ageThis would explain the bandage, the five-o-clock shadow, and how he had so many previous jobs on top of working at Kadic Academy for 20 years. He also never mentioned the real reason he was embarrassed about Paco, King of Disco. It could have been made a long time ago, but Jim still looks about the same.
Mr. Puck's appearances in Aelita's dreams are a mental defense mechanism.Besides the fact that some of her memories were removed from her and stored in Lyoko, she also partially repressed some of them. Mr. Puck is a mental avatar for Aelita (also helps explain why her Lyoko form is an elf), and she remembers herself as Mr. Puck in order to avoid confronting her traumatic memories directly.
Odd is Self-AbusiveThink about it. I can't offhand think of any real episode where Odd wears anything less than long-sleeved outfits. Ulrich knows, which is why he never complains about Odd hanging off of him. He mentions that his sisters abuse him in the most nonchalant of tones, and doesn't seem surprised when a girl pulls something particularly nasty. On another note, William also knows, but doesn't say anything.
William is related to X.A.N.A.William was the most easily possessed of the six, and having a genetic relation could be X.A.N.A.'s 'back door' into William's mind.
Carthage is a larger version of Lyoko
Aelita is not a virtual being who was materialized. Her mother is.That's why they both have pink hair. Aelita's mother has it because she's a computer program, and Aelita inherited it from her. Aelita's father created Aelita's mother, and fell in love with her and managed to materialize her like Jeremie did to Aelita. The Men in Black kidnapped Antea because, being a computer program, she doesn't have rights and is a classified technology belonging to the government. They are after Franz Hopper because he "stole" this classified technology for his own purposes.
There are tons of people trapped in virtual worlds unable to leave like Aelita during the first season.Franz was not the only member of Project Carthage who planned to escape The Men in Black by virtualizing his family. There was a whole team of people working on Project Carthage who The Men in Black are after, and all those who weren't captured by them escaped to virtual worlds powered by various supercomputers all over the globe, which Jeremie calls Replikas and mistakenly assumes were created by XANA. Like Aelita and William, many of them have no memory of being human or are possessed by XANA.
Sissi's mother worked on Project Carthage, and left her family to protect them from The Men in Black.
Both the missing fragment and virus business are both true.X.A.N.A. did steal Aelita's human memories, but he didn't place a virus in Aelita. The virus placer was Franz Hopper. This kept her in a comma if the Supercomputer was turn off. He assumed the gang will believe it was done by X.A.N.A. and Jeremie would try to work on anti-virus. Any anti-virus won't work because the cure for the virus was Aelita's missing human memories. This was to kept the kids busy until he can find Aleita's human memories from whereever X.A.N.A. place them. He got them sometime after the kid took care of X.A.N.A-Franz, so he took over Sissi to give them a message. In the end, after X.A.N.A. escape, Franz give Aelita's memories which removed the virus from her. Christmas Episode Servo defeats the main villain of the show in a one on one fight. But right when he heads off searching for a way to return to home from the digital world a they all got amnesia and the whole world was set back five days in time! My theory is that it was a Return trip that somehow got overclocked, (X.A.N.A, Kilokhan?) and didn't work entirely as everybody who was in Sam's basement just before they did the Return-To-The-Past program remained there. This must mean that the program has a longer range than the Lyoko Warriors realize and it was once overclocked off screen and maybe some flaws in execution. Though how they solved that function and the issues with it are unknown. Admittedly I can't justify the vast differences in appearance and origin from the "Digital Domain" and Lyoko but this is a much better plot than how Superhuman Samurai Syber-Squad actually handled it.
Aelita died when the M.I.B. kidnapped Anthea.The Aelita we know and love? She's an AI Franz created to replace his dead daughter, using her memories and DNA. Alternatively, Franz created her from the original Aelita's DNA only, having been unable to scan her and retrieve her memories/being smart enough to realize giving her fake memories could bite him in the butt later. When he restored her memories in "The Key" he also gave her the rest of the original Aelita's DNA code (thus why she was able to be devirtualized normally from then on). As for why she has memories from before she was created? The answer should be obvious.
Season 1's "The Trap" takes place in on Oct. 12 , 2003.According to "The Trap", it's been one year since the gang meet Aelita. Here's a theory how I come up using the pre-sequel X.A.N.A. Awakens".
The following is a theory of how the gang learn that no one can be brought back with a "Return to the Past" without a death of a human.The second X.A.N.A attack. which happen sometime between "X.A.N.A. Awakens" and "Teddygodzilla" had the virus-like program effect a whole bunch of spiders. Jim told them the kids to get lost until the adults clean the spiders out. The Lyoko Warriors head to the factory — squashing the spiders on the way. The gang got to factory, virtualized into Lyoko, deal with X.A.N.A.'s Bloks and then Aelita shut down the tower with "Code Lyoko". The gang used the "Return the Past" to get rid of the spiders at Kadic. Sometime later, they is a report on a group of spiders dead in the woods outside of town — the gang reason those were the same spider that X.A.N.A had control over and reason that returning the past won't be restore any human or animal.
XANA had already planned to possess William.XANA had noticed how the monsters' AI was no match for human ingenuity and decided to capture a human of his own. He then sent one of his specters to the real world for the sole purpose of implanting memories in William that should have been erased in a return trip. He new that the team was getting desperate at this point and would make the half-baked decision to bring a complete amateur to Sector 5. This would make William an easy target for two reasons. 1) William had no experience on Lyoko, let alone Sector 5, an area that still provided a challenge to the veterans. 2) He new that William would not take it seriously based on observation from the real world and the behavior of the others when THEY were first materialized. This put XANA in the perfect position to capture William, who had the same advantages as the humans (ingenuity) as well as a major power buff from XANA. This also gave XANA a human agent that he could materialize without activating a tower (thus alerting the Lyoko Warriors.)
Waldo Schaeffer/Franz Hopper has created a massive network of Lyoko Supercomputers around the Earth, the Galaxy, and even throughout time, all linked back to the primary Supercomputer located in the abandoned Renault Factory we all know and love.Think about it. The Supercomputer is an incredibly high-tech device, and it couldn't have possibly worked perfectly back when it was brand new and with Aelita's dad at the helm. As per Finagle's Law, anything that can go wrong will go wrong, especially with something that uses a lot of Applied Phlebotinum that can and will be prone to Phlebotinum Breakdown. Sometimes the Scanner cabinets would malfunction while Franz was in them, displacing him somewhere else in space (but always on a planet, except for one case where he ended up on the International Space Station) or somewhen else in time, cutting him off from the Supercomputer as if the Scanner had been a teleporter. In order for him to get back home, he would need to build a new Lyoko Supercomputer and link it up to the one back home—using plenty of Applied Phlebotinum along the way—while Aelita stayed behind to keep XANA in check (prior to his rebellion). After completing this new Supercomputer and its related components, he would recreate whatever Phlebotinum Breakdown that caused the Scanners to malfunction to return back to the home computer, as if he were using a Portal Network. Or, if he ended up on Earth in the same timeframe as the one he entered the Scanner in, he'd build the Lyoko Supercomputer just to make sure that he had a backup computer should the primary one fail and then just booked a flight back to France. The result is a massive network of Lyoko Supercomputers, several hundred of which XANA had direct access to on Earth (and one on the International Space Station) that he reprogrammed to create his Lyoko Replikas, and a handful more scattered through out time and space, each fully functioning and located in a secret location that no one would think to find. Known Supercomputers like this are located in or on:
How did the Warriors know that falling in the digital sea erases them?