Before Yu Takeyama became the famous “hero” you all know her as, she was an adult film actress for the sole purpose of making LOTS of money and became a fast rising star in the industry within just a months time. So much so that she ended up getting recognized by the public almost every time she left her house. Eventually the kind of attention she was getting became too much for her mental health and decided to ditch the industry after a couple months.
Despite her retirement, she still gets noticed and harassed by the residents for her pornographic past. Eventually, she thought about how to get people to stop ogling her and decided that the best idea was to develop a cliché superhero persona that would give herself a new identity. (This works about as well for her as you think.) And thus, Mt. Lady was born. She is treated as a pro-hero in the story despite not having an official heroine license. Everyone just doesn’t question her legitimacy as a superhero.
For Mount Ladys voice, were not looking for anything to exact. We’re looking for a American young adult voice with hints of vanity in it. A good example of the kind of voice were looking for is the side character Tricia Lange from Rick & Morty.
Mount Lady Voice reference - https://www.youtube.com/watch?v=Zp0N5PJxamE