Power point presentation is 57 slides long.
"What is a Myth/Foundation of Greek Myths"
"Earliest Gods and Goddesses"
"Olympic Gods and Goddesses"
"Lesser Gods and Goddess/Creatures of Greek Mythology"
I would teach a section then would work with my students on a chosen activity that related to Greek Mythology.
For example: Creating their own Creation Story using the Gods and Goddesses; Creating a pomegranate to explain Persephone and Hades' story; weaving to illustrate the story of Arachne and Athena, and so forth.