For those who don't know who Aelita is, here's a short summary
Aelita is a native of the virtual world of Lyoko and the sole known inhabitant. She has the unique ability to shut down the towers on Lyoko, stopping Xana's attacks on the real world. On taking up residency in the real world in the second season, she takes the surname of "Stones." She had proven slightly gullible in the real world early on, like when Sissi told her about the showers with no girls in them (they were the boys' showers), but she has adjusted quite well. In terms of personality, she is something of a mix of Jeremie and Odd, in that she can be both reckless and stubborn at times.
After Franz Hopper revives Aelita and completes her human form in the episode "The Key", she gains the ability to attack with energy blasts and can properly devirtualize to Earth (without using the Code: Earth program that Jeremie had created) when losing all of her life points.
Aelita is the younger female in the group and the more naive one of the four, having had comparatively less experience with the real world than her friends. At first thought to be an AI within Lyoko, Aelita's former life is slowly explored as the series progresses. She is the daughter of Franz Hopper, the person who designed both the supercomputer and Xana. She manages to settle into her new life by the start of the third season, making more jokes and generally being less naive in such matters. She also becomes noticeably more daring and brave, reflected in her combat skills after this point.
Aelita wears two different outfits, changing from one to the other over the transition from the first season to the second. The first outfit consists of a maroon skirt, yellow shirt and pink jacket (in "The Key", this is shown to be the outfit she was wearing when she was first virtualized). The second consists of a dark pink jumper dress over a light pink hooded long sleeved shirt and dark pink knee boots. Her night clothes consist of white socks and an oversized pink t-shirt with a red letter A on the front. In the fourth season, her outfit consists of a dark purple dress that comes to her knees and light pink pants underneath. Her boots are a deep red, with each one having two puff balls like the ones from her jumper dress.
Aelita's main interest is music, specifically mixing it, which she has a natural talent for. Her childhood memories show that Franz Hopper taught her to play the piano at an early age. She, like Jeremie, is also a capable programmer and an excellent student, usually assisting Jeremie with the former in her off time. The two also have a close relationship, Aelita having even kissed Jeremie at one point. Unlike Ulrich Stern and Yumi Ishiyama, however, their relationship isn't made as much of an issue, though it's touched upon at certain points.
As revealed in "Xana Awakens", Jeremie Belpois discovers Aelita asleep within the supercomputer after stumbling upon and reactivating it. Aelita, knowing nothing of her past, is nicknamed "Maya" (possibly after the computer software used to create 3D graphics) by Jeremie as a placeholder. She later remembers her name after it's spelled out on the tower interface screen.
Throughout the first season, Aelita is stuck in Lyoko, the program necessary to materialize her still in development by Jeremie. She serves as an early warning system of Xana's attacks, detecting the pulsations from Xana's activated towers and relaying the information to Jeremie. The two talk about the real world at great length whenever they have the chance. At the end of the first season, Aelita is finally materialized, but her time on Earth is short as Xana takes measures to make sure she remains linked to the supercomputer. Jeremie eventually develops a scanning program that removes the need for her to remain there.
During the first two seasons, Aelita's connection to Lyoko also serves as a handicap. Since bringing her to Earth requires a special materialization program used while inside a neutral tower, Aelita would die if she lost all of her life points, adding an extra plot element to the standard "get Aelita to the tower" motif. With the restoration of Aelita's memories at the end of the second season, this handicap is removed.
After Jeremie finishes his materialization program and completes the super-scanner program, Aelita is able to live on Earth on a permanent basis. She enrolls at Kadic under the asumed name of Aelita Stones, Odd Della Robbia's cousin from Canada.
After this point, a few episodes touch upon her relationship with Jeremie, namely his stubbornness and lack of understanding in regards to her interests. He always manages to put things right by the end of such episodes, however.
Near the end of the second season, Aelita learns about her past life, having had visions of it throughout the season. Though initially disturbed at the thought that Franz basically stole her entire life, his sacrifice of his own life to revive her at the end of the season drives her to find him once more.
Powers and abilities
On Lyoko, Aelita's outfit consists of a pink mini skirt and a matching top that go over pants and a long shirt that are both off-white, with maroon gaiters that wrap around them, and matching shoes. She also has elf-like ears, with a small dangle earring in the left one. Aelita's Lyoko ID card has a pink Eye of Xana on the back. For long-distance travel, she usually rides with one of her friends, but uses any available vehicle when alone. She also serves as the main pilot of the virtual ship Skidbladnir, with her friends operating a series of "NavSkids" in conjunction.
In the fourth season, Aelita receives a new pink form-fitting suit on Lyoko, in addition to a transparent skirt and other similarly transparent adornments. The suit has a pair of retractable, angelic energy wings, enabling Aelita to fly; she simply has to wave her hand over the star-shaped bracelet she wears to create them. However, if she takes damage during flight, the wings disappear.
Aelita's weapon on Lyoko (which she didn't receive until the third season) are her "energy fields", energy orbs created in the palms of her hands capable of destroying any monster on contact. The orbs cover a target with energy on contact (hence the name) to destroy it, regardless of where they strike. It is also capable of shattering even the elliptical laser of a Megatank in two hits. The drawback is their creation, which takes several seconds. Aelita can also amplify the effect into a single massive energy orb, which is powerful but exhausting to use. Additionally, Aelita can create a makeshift shield by forming an energy orb in each hand and mixing their energies. The shield, while powerful, has a very small surface area and takes precision aim to block attacks, though they can hold off the Megatanks' lasers for a short time.
Aelita's main purpose is to deactivate the towers activated by Xana, stopping his attacks in the real world. She accomplishes this by accessing the interface at the top of the tower and entering the code "Lyoko", which shuts the tower down.
Aelita's skill on Lyoko is that of spontaneous generation or destruction of matter, referred to as "creativity" (in the episode "Rock Bottom"). Using this power, Aelita can create anything she wants on Lyoko, or remove sections of land, though doing so costs half of her life points for each use. Her power is normally used to create barriers or other such surface features to stall the advance of monsters. She also creates a powerful energy barrier in "Replika". The shield is red in color, and can take only so much damage before finally shattering. She can also create simple clones of herself or others. The clones possess no will of their own and have a limited range of movement, basically only running in a straight line, but are nigh-indestructible. She also possesses some sort of second sense which allows her to see the landscape of Lyoko when invisible, as seen in "Attack of the Zombies", but it seems to be ineffective by "Tip-Top Shape".
Aelita and the virtual World : Code Lyoko season 1
Thought the firsts episodes of the first Code Lyoko season, we can quickly see who is one of the series main character. With her very uncommon pink hair, her mint-green eyes and always with this smile on her face, Aelita is a 12-year-old, young and cute little girl. Apparently, nothing that strange for now, but what makes her so particular and different is that Aelita isn't really Human. In fact, she lives in a virtual world called Lyoko, and as the main guardian of this virtual world, she is, in an extend, rather linked to it. It's say that while Jérémie and his friends at start, turned on the supercomputer, they all promised one thing together: to be able to materialize Aelita with the help of the scanners, make her security and give her a brand new life on Earth.
Actually, on Lyoko, Aelita's worst enemy is X.A.N.A. With his monsters, X.A.N.A. wants one thing: to destroy her and then take the control of both the virtual, and the real world. Aelita is the only one that can stop X.A.N.A. in his plans. By deactivating towers on Lyoko, with the so called Code Lyoko, she can stop X.A.N.A. right before he can do anything really wrong. But Aelita is constantly in danger, and if she get hit several times until her live points finally reach 0, or if she unfortunately fall right into the numerical sea, the fact is that she can't come back to Earth that easily unlike the others, and she will disappear forever. It's like a whole game for life, a game that you shouldn't lose...
While Jérémie, Ulrich, Yumi and Odd are at school, on Lyoko, Aelita still going in circles visiting all four different territories turn by turn. She is overlooking the place in case X.A.N.A. finally shows up some activities. It can be some monsters to make her fall right into a trap while her friends are away, or in the worst case, great pulses that imply an active tower and huge problems to come, both on Earth and Lyoko. Just like X.A.N.A., she can control communication networks on Earth, and then, she is able to warn our Lyoko warriors just in time. Sometimes however, for various reasons, nobody can help her at all. Then, she has to do the dirty work herself, and take huge risks to save her friends, and the World.
It's a fact, Aelita is weak, but strong at the same time. Her defenses reaches absolute zero, and she can't directly attack X.A.N.A.'s monsters like our others heroes. Anyway, she is very smart, she know very well how X.A.N.A.'s monsters react, their common tactics, and she know exactly too, where to go hide herself from them, just in case. In addition, she has some powers. She can easily mislead X.A.N.A.'s monsters by cloning herself or something else, to lure them. But her best and most spectacular power is certainly the ability to create or destroy some environments blocks. These blocks can open new ways to go and escape, or stop monsters for a little while in their chase, to gain some precious time until our Lyoko warriors finally arrive at the rescue. These amazing powers however, because of their strength, are all supposed to use the half (50) of her own life points. Then, she is unfortunately far from almighty...
After weeks of hard work, finally, Jérémie found one way to materialize Aelita: the Code Earth. Once on Earth, the fact is that our little Aelita is rather lost: she know about nothing about every-day's life in the real world, and then she start feeling like humans, cold, warm, smell, taste... etc, some things again remaining unknown for her. With the great help of her friends, Aelita try to start her brand new life: she lives at Yumi's home as a pen-friend from Japan, known as Aelita Lyoko, and she assists at college Kadic lessons, as Odd own cousin coming from Holland. This, at least until X.A.N.A. strike again... Before materialization, X.A.N.A. found the way to implement something that looks like a virus inside Aelita. This virus simply permanently link her to the supercomputer, and it appears that there is no way to turn it off without killing Aelita at the same time. And then, Aelita should still on Lyoko until this problem is solved. This is now the start of a new adventure.
Aelita's origins : Code Lyoko season 2
The second season of Code Lyoko is mainly focused on Aelita. After X.A.N.A.'s last attack that sticked her on Lyoko for a while, Jérémie succeed to program a Super Scan, so that his beloved virtual girl can return on Earth without worrying that much about X.A.N.A.'s actions. Now, Aelita is known as Aelita Stones at Kadic school, and is yet again Odd's own cousin. But fastly enough, it appears that Aelita has some mind and memories problems: she feels like she had already lived here, on Earth, even if it's theoretically impossible. Often, she can see her thought visions living in a sweet house called "Hermitage", house now abandoned inside the forest near Kadic school. Several times, she makes nightmares of these visions that seems more and more accurate, and then, some strange things and coincidences are revealed.
First, her visions aren't that false at all. To everyone's surprise, she discovered an unknown passage that links the "Hermitage" to the factory through sewers. And, even more important, she discover a small doll, doll that she can even remember its name: "Mister Pück". This doll carried one key that linked our heroes to Franz Hopper's encrypted Diary. All the second season long, Jérémie try to decipher this mysterious Diary, and at the same time, X.A.N.A. changes his strategy. Now, it appears that X.A.N.A., with the help of brand new powerful monsters (like the Medusa), doesn't want to kill Aelita anymore on Lyoko, but instead, he wants to steal her memories...
Little by little, more information are displayed, and thanks to the discovery of a new 5th territory on Lyoko, the Carthage territory, even more information about X.A.N.A. and this weird virus are found. Jérémie even manage to decipher Franz Hopper Diary, but at the same time, X.A.N.A. gains more and more powers, and at the end, he succeed in his dark plans... He finally manage to steal all Aelita's own memories with the help of the Medusa, and then, combining this and the Franz Hopper Diary, huge things are revealed once again!
First very important thing, Aelita's origins aren't what we were thinking, she is 100 percent Human. She is actually Franz Hopper's own daughter, and her real name is Aelita Hopper. Both were virtualized on Lyoko. But we can only imagine that some events were going wrong: once on Lyoko (hypothesis), Franz Hopper was captured, and Aelita lost all her real life memories rather instantly. At the very end, it's said that both Aelita and Franz carry the Keys of Lyoko, a real gateway between the virtual world and the real world. It appears that because of these Keys, Aelita is linked to the supercomputer, and she was in fact, never infected by X.A.N.A.'s virus. These Keys of Lyoko is actually what X.A.N.A. searched all the season long inside Aelita's memories, and then he succeed to escape the supercomputer once his task accomplished.
Hopefully, Franz Hopper managed to gain some extra controls on Lyoko. At the very last minute, he save Aelita from death, and she recover all her memories. Now, she is free to live on Earth, but X.A.N.A. is free too. Here are her past Earth memories: before she was virtualized on Lyoko, Aelita was a cute little girl living with her parents, on a snowy mountain. At Christmas day, she even got "Mister Pück" as a present. As we can see, she was already quite open minded, her father teaching lessons for her. But unfortunately, Aelita lost her mother, supposedly by accident. Then, this little family decided to change their life, and they moved to the "Hermitage" near Kadic school. The end of the story, we already know it: once Aelita was 9 or 10 years old, Franz Hopper, constantly chased by Men in Black because of his actions, run away with his daughter and both, carrying the Keys of Lyoko, they were virtualized, forever...