Villain Hera is the main villain of the myth. The villain is someone who opposes the hero and makes their quest difficult. Hera is the main villain because of how she made Her uses hurt his family.
Hercules was an incredibly mighty Greek hero. Despite all his great power, he did not know his own strength. His greatest strength was also his greatest weakness. Flaws like this are extremely common in Greek heroes. This reflects how the Greeks greatly valued humanity in their mythical characters.