Hamilton, a Scottish alchemist, conducted unethical experiments on his daughter Lili, granting her psychic abilities to read minds and sense emotions. These daily procedures involved harmful medications causing fits and blood-coughing, creating dependency on stabilizing treatments. His singular focus was acquiring the Philosopher's Stone, believed embedded within the alchemical gargoyle Gar-kun. To obtain it, Hamilton orchestrated events, manipulating Lili into infiltrating the Yoshinaga household and befriending Gar-kun under false pretenses. He later deceived the phantom thief Hyakushiki into collaboration, falsely promising the stone could cure Lili while intending to seize it for his own research. When Gar-kun surrendered to Hyakushiki to save Lili, Hamilton betrayed both, shooting Hyakushiki and commanding his robotic creation Dullahan to capture Gar-kun. His actions consistently prioritized alchemical ambition over familial bonds, exploiting his daughter as a tool without remorse for her suffering. His downfall came when other alchemists, including Amane Higashimiya, intervened to protect Gar-kun, thwarting his plans and exposing his ruthless methodology and ethical disregard. Hamilton remains defined as an antagonist whose power-driven pursuit through alchemy starkly opposes the series' themes of community and protection.