Master Berthold Hawkeye was Roy Mustang's mentor and Riza Hawkeye's estranged father—a brilliant alchemist whose work with flame alchemy shaped everything Roy would become.
Hawkeye developed the complex theories that made flame alchemy devastatingly powerful and efficient, but he refused to teach Roy the full extent of his secrets. He thought Roy was too young and reckless to be trusted with that kind of knowledge. Riza remembered him as a frightening, distant figure she could barely relate to. The relationship was clearly strained, if not outright broken.
Paranoid about his life's work falling into the wrong hands or being destroyed, Hawkeye refused to write anything down. Instead, he tattooed an enormous Transmutation Array containing all his accumulated knowledge directly onto Riza's back. Whether that decision reflected the family's problems or made them worse is hard to say—but it's not exactly the move of a father trying to get closer to his daughter.
Like Izumi Curtis, Hawkeye had little use for the State Military. He made his disdain clear when Roy enlisted during the Ishval Civil War, and he'd rather live in poverty surrounded by his work than join the State Alchemist Program and compromise his independence.
When Roy eventually returned to his teacher's house looking for the flame alchemy theory so he could become a State Alchemist, Hawkeye revealed the truth: everything Roy needed was tattooed on his daughter's back. He died in Roy's arms shortly after, coughing up blood as his illness finally took him.
Content compiled by AnimeList.moe from publicly available sources.
