Fabia Sheen, a princess of Neathia during the conflict in *Bakugan: Gundalian Invaders*, fights to protect her homeworld from Gundalian aggression. She is the younger sister of Serena Sheen, Neathia's former queen turned ambassador, and Fabia herself later ascends to become Queen Fabia. Her appearance features blue hair and green eyes. Disguised as human, she wears a white-and-orange robe with rings, blue boots, and pink earrings. Her true Neathian form reveals purple skin and large, round green eyes. As a member of Neathia's elite Castle Knights, she dons form-fitting combat armor with yellow and silver trim. Her royal attire as queen mirrors the robes once worn by her sister. Fabia's personality blends determination with significant growth. The death of her fiancé, Jin, killed by Gundalian agent Kazarina, fuels deep resentment toward Gundalians. Fabia rescued Jin's original partner, the Haos Bakugan Aranaut, from Gundalian experimentation, an act of rebellion against her sister's orders. Aranaut, who lost all memory of Jin due to Kazarina's procedures, becomes her primary partner Bakugan. Her grief initially drives a vengeful outlook, but witnessing shared betrayal by Emperor Barodius leads her to gradually trust former enemies like Ren Krawler and Nurzak. This development culminates in a symbolic duel with Ren, where she accepts his redemption and permits his induction into the Castle Knights. She also shows empathy toward Lumagrowl, Kazarina's partner Bakugan, after Kazarina's demise. In *Bakugan: Mechtanium Surge*, Fabia rules Neathia as queen. As part of her royal duties, she relinquishes Aranaut to Captain Elright, retiring from active brawling. Haos Exceed Wavern, equipped with the Silver Daybreaker Battle Gear, becomes her new guardian Bakugan. During this era, she collaborates with Almaz Vontana as part of Team Grey, maintaining her leadership role. Her combat record includes victories against Stoica, Jesse Glenn (alongside Jake Vallory), Ren Krawler (alongside Almaz Vontana), and brainwashed brawlers (alongside multiple allies). She suffered defeats against adversaries like Dan Kuso, Zenet Surrow, and Kazarina. Notable moments showcase her physical strength—overpowering Dan Kuso and thwarting Zenet's hostage attempt—and strategic cunning, such as coordinating Bakugan swaps with Shun Kazami to deceive opponents. After becoming queen, her narrative focus shifts toward governance and alliance-building, transitioning from frontline combatant to planetary leader. Her legacy intertwines themes of loss, forgiveness, and the burdens of leadership.