Interestingly, this backstory could make her a hero as well as a villain, depending on what she considers a "better world", and what she's willing to do to make it "better". I have a character who wanted to help people out of their misery, but that character also believed people were the source of their own misery, so they used a gentle mindcontrol to suppress peoples' evil side and remove selfishness. However, betrayal from those they trusted, and those they wanted to help eventually made them go mad, basically going "If you refuse to let me build a paradise for you, I'll beat you until you stop resisting! You will live in happiness, if you want to or not!" Didn't end well for anyone.
Interestingly, this backstory could make her a hero as well as a villain, depending on what she cons