Fabia Sheen is a Neathian, and the new Haos brawler for Gundalian Invaders. She uses Aranaut as her Guardian Bakugan. She is the sister of the Queen of Neathia, Queen Serena, and is brawling in order to save her. She uses Battle Crusher as her Battle Gear. It is highly possible that Fabia sent the Phantom Data, mostly because when she arrived in Bakugan Interspace she was wondering if anyone got her message, plus her Guardian Bakugan is the same as one of the virtual Bakugan in the Phantom Data Marucho received. She seems to have some kind of Mira's initiative and love for freedom. She also seems to be strong, because she threw Dan in episode 3. She uses a real Aranaut which most likely proves that she sent the phantom data.

As a Neathian, she looks like her sister. As a human girl, she has blue hair and green eyes. She wears a white and orange robe with a yellow, orange and white robe with rings and white and blue boots (Similar to Runo's New Vestroia outfit). She also has pink earrings.

She first appears in episode 3 (Bakugan: Gundalian Invaders) and brawled Dan Kuso with Aranaut, Fangoid, and Merlix, but lost. After losing, Dan gloated about his win, telling her that she shouldn't use the Bakugan for war, and that hostile forces like her were not welcome in Bakugan Interspace. Because of that, she decides to throw him and leaves, telling Dan that he didn't know anything. Later, Shun Kazami finds her and asks to hear her story.