Code Lyoko - Season 2 - Eps 21: Tip-Top Shape
During the school physicals, Xana possesses the school nurse, Yolande, and has her kidnap Aelita. The rest of the group beats her to the factory, but has no way to get Aelita from the far more powerful nurse. Having no other choice, Jeremie decides to test out an experiment which will give a person the same powers as one possessed by Xana. To do this, he has to activate a tower like Xana. Jeremie's towers turn green instead of red. Odd volunteers, and is enhanced by a ghost of Jeremie's design. This allows Odd to fight the nurse effectively while the others deactivate the tower. This fortune doesn't last, however. Xana is able to take over Jeremie's tower, reversing the effect of the ghost to drain Odd's energy. And on Lyoko, Xana makes everything invisible. Now the group has to deactivate not only the original tower, but the tower that's draining Odd's energy.
About Code Lyoko

Title: Code Lyoko
First Air Date: 2003-09-03
Last Air Date: 2007-11-10
Status: Ended
Rating: 7.463/10 (from 81 votes)
Language: FR
Seasons: 5
Total Episodes: 95
Network: France 3
Genres: Sci-Fi & Fantasy, Animation, Comedy, Action & Adventure
Production Companies: MoonScoop, Antefilms Production
Synopsis
Four children travel to the virtual world of Lyoko to battle against a sentient artificial intelligence named XANA, with a virtual human called Aelita.
Cast

Raphaëlle Lubansu
Jeremie Belpois / Odd della Robbia (voice)

Géraldine Frippiat
Yumi Ishiyama (voice)

Marie-Line Landerwijn
Ulrich Stern (voice)

Sophie Landresse
Aelita Schaeffer (voice)

Mathieu Moreau
William Dunbar (voice)

Carole Baillien
Sissi Delmas (voice)