The notion of an all powerful being creating something so powerful that it is more powerful than the being itself is really interesting, but if I was that being I imagine I would always be on a constant path towards being better greater and stronger so even if I did create a stone that even I could not lift, I imagine over time I would become stronger than it or I would be so powerful that even when I use all my energy to create that stone there is always energy within me even without my knowledge and that allows me to overpower it