Hello! I'm Strongest Demon

Hello! I am Sirius Diabolus, the strongest demon in the world. Unfortunately, fate took its course as it should have and I was defeated by Hero and his party. But it seems they don't realize how powerful even the soul of the strongest demon in the world can be because I have reincarnated. The problem is, I reincarnated as Hero's "daughter". I wonder how my life will be now?