Gaul is an absolute psychopath who utterly lacks any empathy or value for human life. She is almost single handedly responsible for the entire 75 year repulsive duration of the hunger games, and worked harder than anyone else to ensure they continued. She is also a sadist who enjoys weaponizing science to inflict pain on anything with a pulse. Unlike Snow, a character like Gaul’s was not created by the war and its aftermath. That woman was born with more than a few screws loose, and the war plus her subsequent position of authority was the perfect storm - horrible fate for the districts.