Sellon is a new character in Super Smash Bros. Crossover. Like in Mechtanium Surge, Sellon was intially an antagonist. She is a Neathian and a servant of Mag Mel along with Anubias. Her Guardian Bakugan is Spyron. Sellon and Anubias are the primary antagonists of Season 9, and are responsible for most of the events in Season 9, but Sellon is ultimately defeated for good by Fabia. In Season 10, Sellon is still an antagonist, but is now more of an anti-hero. She intially aides Psycho Kirby, Zombie Spider-Man, Ren, Sasuke, Ben, Luigi, DK and Samus in their struggle against Zombie Reed and Smithy, but is hesitant once Mag Mel and Xaos arrive, due to still having loyalty to Mag Mel. Afterwards, she is blasted away by a brainwashed Samus to Hyrule Temple where Anubias currently is before they are ambushed by Mag Mel. As Anubias is about to be defeated by Mag Mel, Sellon has a change of heart, and finally joins the battle against Mag Mel, sucessfully defeating him. In Season 13, Sellon and Anubias have their final battle against Naruto, where it is revealed that Sellon and Anubias are artificial beings created by Mag Mel. Despite having an advantage at first, Sellon and Anubias are defeated and they shatter into a million particles of light which are absorbed into the Smash core. Sellon and Anubias are notably the only characters that are not revived at the end of Season 13. In Season 14, Sellon and Anubias appear as spirits to aide Naruto in battle. Sellon and Anubias appear during the finale to support Naruto in the final battle against Pandoria. However, Jinzo turns the battle/duel into a Shadow Duel/battle and puts Sellon, Anubias, and Yugi Muto's souls at stake. In Season 18, Sellon and Anubias are forcibly revived when Yami Bakura uses the Millennium Ring to force them out of Naruto's body. Sellon is a curently a member of the Heroes of Legend. In Season 20, Sellon and the other Heroes of Legend fuse with Naruto in order to help him purify Samus Aran. After the battle, Sellon is restored on the Space Colony Ark, and mourns the death of Samus and the apparent death of Sasuke and Drago. In Season 22, due to a mishap on Piccolo's part, Sellon becomes a Dark Hero of Legend, but is accidentally freed when Wiseman revives himself after his botched self-destruct. Later, Sellon tells Anubias that she is confused after she heard Mag Mel's voice when they were helping Gohan, but is comforted by Anubias. However, Sellon hears Mag Mel in her sleep, causing her to revert to her original purpose. The next day, Sellon and Anubias change some of the rules of the Neo Smash Champion Tourney to increase the intensity of the battles so they can revive Mag Mel. Sellon then manages to distract Naruto Uzumaki and Goku by arranging for Naruto to battle Team Samus and reminds Goku he can finally have that battle with his son Gohan that he promised. Sellon then proceeds to kidnap Serena Sheen in order to blackmail Fabia Sheen into battling with Ren against her and Anubias on the Ivory Towers. Sellon then witnesses as Mag Mel's influence causes Fabia and Ren to go beserk, upsetting Sellon as she initially thinks Mag Mel is betraying them, but is told by Mag Mel that he isn't betraying them. Later, Sellon witnesses Gohan's struggle against Samus, and is so touched by his bravery that she overrides her original purpose and destroys Time Eater. Sellon and Anubias then play a pivotal role in destroying Samus for good. Later, Sellon and Anubias sacrifice themselves to stop Wiseman from gaining control over the Heroes of Legend, despite the fact that they are the only Heroes of Legend that are still alive. Sellon is later revived when Bowser forces the Offspring of Zorc out of the Millennium Ring, which was with the Heroes of Legend at the time. In Season 23, Sellon assists her friends during the Mechtogan War Arc, but after the death of Anubias, Sellon loses her will to fight, resulting in her death at the hands of Slycerak. Sellon is later revived by the others' energy. Sellon later accompanies the Dark Heroes of Legend into the realm of the Mechtogan, but is killed by Mechtavius Destroyer along with Anubias. Sellon is revived in Season 24 due to Drago killing Mechtavius Destroyer in the past. In Season 30, Sellon, along with Anubias, Zenthon, Zenthon Titan, the Nonet Bakugan, The Dark Surfer, and the Bakugan belonging to Anubias and herself, sacrifice their lives in a final attempt to save the multiverse from Mechtavius Destroyer. Sellon is later revived in Season 31 when Naruto and Drago go back in time and cancel out her death.
Sellon's main appearance is based off her Mechtanium Surge appearance. In Season 22, it is revealed that Sellon has a white bathing suit, though this was a "4Kids edit" to keep this series rated TV-Y7 FV.