Zeus
Zeus played a dominant role, presiding over the Greek Olympian pantheon. He fathered many of the heroes and was featured in many of their local cults. Though the Homeric "cloud collector" was the god of the sky and thunder like his Near-Eastern counterparts, he was also the supreme cultural artifact; in some senses, he was the embodiment of Greek religious beliefs and the archetypal Greek deity.
Phthonus
In Greek mythology, Phthonus (, "Phthónos") was the personification of jealousy and envy, especially in matters of love. He was said to be the counterpart of Nemesis. However, his power influenced not only himself and mortals, but also the gods as well (most famously Hera). It was he that directed Hera's attention to Zeus' many affairs, including one of his most famous, that with the Theban princess Semele. He also put the thought into Hera's mind to trick Semele into convincing Zeus into showing Semele his full glory, which killed her.