The theme of the myth of Prometheus and Pandora's box is the dangers of curiosity and the consequences of disobedience.
In the story of Prometheus, the phase that supports this theme is when Prometheus disobeys Zeus by giving fire to the humans, which angers Zeus and leads to Prometheus being punished by being chained to a rock and having his liver eaten by an eagle.
In the story of Pandora's box, the phase that supports this theme is when Pandora disobeys the gods by opening the box, which unleashes all the evils of the world and causes suffering for humanity.
Both stories illustrate the dangers of curiosity and disobedience, and the consequences that can come from acting against the will of the gods.