|First appearance||X.A.N.A. Awakens|
|Age||13 years old|
Elisabeth "Sissi" Delmas is an often mean, spoiled and popular student at Kadic. She is also the daughter of Mr. Delmas, the principal of Kadic, the boarding school she attends and lives in. She is a major recurring character. She often pesters Team Lyoko, most of the time to win Ulrich's affections. However, she admits in Holiday in the Fog that she is gaining their attention through her mean actions towards them. By so doing she is almost making enemies out of her would-be friends, instead of gaining any of their respect, much to her chagrin. In Echoes, she achieves this at last and becomes an official friend of the group. In season 5, Sissi falls under X.A.N.A.'s after discovering the supercomputer in "Requiem", and she's scanned and virtualized on Lyoko, for have immunity to the Time Reversion, and she actives the reversion twice for make X.A.N.A. stronger and place a virus into Aelita.
In "X.A.N.A. in School", X.A.N.A. sends to Lyoko where she can disintegrate items. X.A.N.A. materializes Sissi again at Kadic. Days later returns to Lyoko to try to throw Aelita into the Digital Sea but fails and jumps into the Digital Sea to meet his new owner, X.A.N.A. Since then Sissi is possessed by X.A.N.A. and uses a similar powers to X.A.N.A.-William, and have the power of disintegration.
In "Underwater Adventure" Sissi appears in the Digital Sea with the Rorkal, supposedly is the same as used by X.A.N.A.-William in season 4. In "The Big Loss", Sissi is rescued by Lyoko-Warriors ending battle against X.A.N.A.-Sissi, but only is materialized her body and not her spirit. In "In Search of Sissi", Lyoko-Warriors do a mission in the Digital Sea and find the spirit of Sissi, and Sissi returns to normal.
Sissi is integrated into the Lyoko-Warriors in "Rescuing Anthea" when goes to Lyoko to help Aelita, and she had no other place to go because Taelia expelled from her old group. On a mission in "The Great Battle" Sissi goes with Odd to the International Space Station. In the last episode of the season, "The Last Days, Part 2", she almost is re-possessed with the Scyphozoa and Lyoko-Warriors decided that Sissi better will stay in the Factory.
- ID Card: The back of Sissi's card shows a lot of hearts.
- Health: 100 Life Points
- Pink sword - she has two Tessen Fans, lanced as Boomerangs, which also serve as a shield.
- Lyoko Powers/Abilities:
- Lyoko Powers/Abilities:
- Pink spirit - An ability much like William's super-smoke, but instead of become smoke, she becomes an energy pixels to pass away from people, monsters or things. Since he has no vehicle, this is his only transportation.
- Disintegration - This power is the opposite of Aelita's creativity. This ability allows Sissi to disintegrate items of Lyoko.
- Levitation - An ability that allows him to levitate by holding his pink sword by both hands and pointing downward. Only available under control of X.A.N.A.
- Tower Control - Ability to activate a Tower for X.A.N.A., from the inside or outside. This mimics Aelita's power and it is possible X.A.N.A. allowed him to use a version of the Annex Program. Only available under control of X.A.N.A.
- Vehicle: She don't have a vehicle, and uses the pink spirit for desplacing into Lyoko.
In this alternate continuity based off the pilot of the show, Odd sees a picture of Sissi on Principal Delmas' desk. However, unlike her canon counterpart, this version of Sissi has brown hair as opposed to black, which is a reference to Sissi having a slightly different appearance in the original bible for the show. Despite this indication of her presence, Sissi herself has yet to appear or be directly mentioned in Garage Kids for reasons unknown…