Dr. Giovanni, known as Plague Mask, is a Second Generation pyrokinetic. He served as captain of Special Fire Force Company 3 while secretly belonging to the White-Clad, an organization dedicated to triggering a second cataclysm using the Adolla realm. His ancestors collaborated with the Joseph family and Haijima Industries to build the Amaterasu Generator, aware it would facilitate this cataclysm. Trained as an apprentice under Vulcan Joseph's grandfather, Giovanni departed the workshop on the day both Vulcan's grandfather and father simultaneously transformed into Infernals, implicating him in their deaths. He later joined Haijima Industries, using their resources to monitor Adolla's emergence and blacklist Vulcan from merchants, restricting his access to materials. His signature plague doctor mask and top hat were initially worn with a Fire Force uniform, later replaced by White-Clad attire featuring cross patterns. Giovanni extensively modified his body with mechanical and insect-like traits: compound eyes, pheromone-sensing antennae, and the ability to disperse into swarms of fire bugs for evasion and combat. These modifications provided enhanced durability, artificial Adolla Links for communication, and consciousness transference via parasitic bugs that infiltrate hosts' brains, enabling him to prolong his life by jumping bodies. Giovanni advocated placing Shinra Kusakabe in protective custody to exploit the Adolla Burst, a proposal rejected over experimentation concerns. After revealing his White-Clad allegiance, he orchestrated attacks on Vulcan's workshop to steal the Key to Amaterasu. He shot Vulcan's apprentice Yū to force compliance and destroyed Vulcan's possessions when resisted. During these confrontations, he manipulated his subordinate Lisa Isaribe (Feeler), using her as a hostage and threatening her life to coerce Vulcan into shooting Captain Obi. Securing the Key, Giovanni intensified self-experimentation in the Nether, further mutating into insectoid forms to deepen his Adolla connection. He ambushed Company 8 during their Nether investigations, demonstrating heightened abilities like rapid regeneration and pheromone-based emotion sensing. In his final confrontation, he possessed Yū's body to initiate a disaster but was defeated by Vulcan and Obi. Arthur Boyle ultimately incinerated him, ending his plans. Giovanni exhibited a methodical and deceptive personality, masking callousness beneath scientific curiosity. Once exposed, he displayed fanatical devotion to the Evangelist, dismissing human life as expendable for global destruction and reveling in cruel manipulation, such as psychologically torturing Vulcan and abandoning Lisa when compromised. His inventions, including extendable arms with electrified wires and concealed weapons, prioritized offensive capability over durability.