Professor Clay Fermin functioned as the lead scientist for the Vexos, an organization tied to the Vestal royal family. He fathered Keith Fermin, known as Spectra Phantom, and Mira Fermin, who commanded the Bakugan Battle Brawlers Resistance. His research centered on crafting advanced Bakugan technology and weaponry for the Vexos and King Zenoheld. Clay pioneered Mechanical Bakugan, synthetic versions of organic Bakugan. His first successful models included Ventus Altair, tested by Lync Volan, and Darkus Hades, assigned to Shadow Prove. Later upgrades comprised Pyrus Farbros, Subterra Dryoid, Haos Boriates, Aquos Macubass, Darkus MAC Spider, and Ventus Aluze, engineered to harvest attribute energy from the Six Ancient Warriors of Vestroia. His weapon developments featured the Bakugan Termination System (BT System) to eliminate organic Bakugan on New Vestroia. After Drago destroyed the BT System, Clay constructed the Alternative Weapon System (AWS) under Zenoheld’s orders, a device capable of annihilating planets and targeting both Earth and Vestal. Clay operated as a driven, morally rigid scientist, frequently valuing research above family bonds. He showed scant affection for his children, coldly informing Mira that Keith was "no more" and avoiding familial talks. Nonetheless, he sporadically protected their safety, like shielding Mira from debris during the AWS collapse. He harbored fierce loyalty to Zenoheld, fearing professional failure, yet expressed occasional wariness toward Vexos members such as Shadow Prove. Clay also demonstrated pragmatic caution, warning Lync Volan about penalties for treason. Earlier events shaped his background: an encounter where he dismissed Mira’s questions about Bakugan in his lab spurred her to join the Resistance. Though Keith’s transformation into Spectra Phantom occurred under ambiguous conditions, Clay later aided Spectra by upgrading Helios into Cyber Helios and Cyborg Helios. He also secured Mechanical Bakugan for Spectra meant for Prince Hydron. During the Vexos-Resistance conflict, Clay installed the Vexos Trap Field in the Motherpalace arena to sap power from organic Bakugan mid-battle. He rebuffed Spectra’s offer to defect, opting to serve Zenoheld. Post-AWS completion, he trapped Brawlers in a virtual realm for system testing. In his final moments during the AWS implosion, Clay shoved Mira from falling wreckage but became ensnared himself. He refused rescue by Keith and Mira, walking away while apologizing to Mira. His last act involved viewing footage of the Gundalian-Neathian war before dying in the AWS blast alongside Zenoheld and Hydron. Later series referenced Clay: Bakugan: Gundalian Invaders noted his reception and analysis of the "Phantom Data" transmission depicting the Gundalian-Neathian war. In Bakugan: Mechtanium Surge, Dan Kuso observed Mira’s scientific career mirrored her father’s work, and she contributed to Bakugan City’s development.