Acheron was a powerful sorcerer who had a desire to rule over the Magic Dimension. He was the one who created the Legendarium, but was subsequently trapped in one of its pages. The Legendarium was kept in the lost Library of Alexandria, until it was discovered by the Fairy Godmother Eldora and her protege Selina. Acheron was able to convince Selina to help free him by promising her power, transforming Selina into the "Witch of Snakes". One night, Selina stole the Legendarium from Eldora and fled with it, beginning her quest to release Acheron from its pages.
Acheron has light tan skin, glowing yellow eyes, a crooked pointy nose, and a black goatee. He has black marks (which might be Kohl) around his eyes with triangular black marks on its edges.
His outfit is similar to the Dark Witch outfits of the Trix, consisting of a thigh-length armour-like tunic with a hood and large hanging sleeves and baggy trousers tucked in boots. It is red with black marks, the part on his shoulders is pale greyish purple and it has a yellow ruby on his chest.
In "The Golden Auditorium", after the Treants failed to take over Linphea College, it is revealed that Selina is in fact working under the orders of a mysterious dark being called Acheron housed inside the Legendarium.
In "The Fairy Godmother", Eldora tells the Winx the past about Selina and Acheron where she agrees to work under him. Then Acheron gives a bit of power to Selina, dubbing her the Witch of Snakes. Eldora comes in and tells Selina not to read from the Legendarium and warns her of Acheron as the sorcerer who created the book and wound up trapped in its pages. One night, Selina made her decision and pledged her loyalty to Acheron. She stole the Legendarium and fled the Forest of Flowers. Eldora fears that Selina is trying to free Acheron all this time.
Later, Selina had an intention of stealing Bloom's Dragon's Flame because it is the only method to release the book. During the struggle between Bloom and Selina, she tells him that Acheron is his friend and had forgotten Eldora, leading Bloom to defeat Selina without giving despite warn of Acheron.
In "Mystery of Calavera", Selina contact Acheron because she is annoyed that the Trix won't share their powers. Then, He tells Selina to send the Trix into the Legendarium World to defeat the Winx. In each mission, the Winx finds an item to lock the book, Selina makes mention to Acheron saying that if the Winx complete their mission then he could not released.
In "Acheron", Acheron is freed when Selina uses the part of the Dragon's Flame that she stole from Bloom and traps the Trix inside the Legendarium and fights Bloom one-on-one in the Legendarium World. Bloom uses the legend of Alfea against him and successfully traps him in a box given to her by Eldora.
As the creator of the Legendarium and a powerful sorcerer, he can invoke any powerful creature to attack its enemy. Even when he was trapped in the Legendarium, he was able to do things like teleport Selina to the Lost Library of Alexandria. When he was free from the Legendarium, he was able to create lightning and bursts of dark magic and also showed to be powerful enough to send the Trix into the Legendarium and make Cloud Tower fall. He can also create some dark magic to protect himself (to hold Bloom's Dragon's Flame). When he created the Legendarium, he was stronger than his opponents (except for the Dragon's Flame, with the Winx's Bloomix.) Acheron may know some basic, first-level spells that all wizards can use, such as telekinesis, transmuting objects, fixing minor messes. Like all wizards, he can fly. He can also shoot red beams of energy out of his hands.
Uses of Magic
- According to Greek mythology, the Acheron is one of the five rivers of the Greek Underworld. The spirits of the dead had to cross the Acheron on a boat to enter the Underworld.
- The main Season 3 villain, Valtor, also wanted to become the greatest sorcerer of the Magical Universe.
- He is the first villain who appeared as voice only in most of the episodes instead of a person.
- He is the only villain who appears physically once.
- Apparently, he can be considered the weakest antagonist because he has his physical appearance in only one episode but unlike Darkar and Valtor, he is only captured and not destroyed.
- Acheron's voice actor also voices Riven and Rumpelstiltskin in the Nickelodeon dub.
- Since the moment he got freed, Acheron is the only villain that was defeated the fastest.
- In 3D his eyes glow while in 2D they do not.
- Currently, both Acheron and Kalshara are the only antagonists that are neither featured nor mentioned within the Winx Club Comic Series.