Many millennia ago, the gods defeated the titans and their leader, Kronus, the god of time. Zeus credited himself as the hero in the war, having slain his father, and the power went to his head. See, Zeus has a great fear and weakness, one shared by both mortals and immortals; he loves power, and will go to great measures to keep his high position. He proclaimed himself king before any of the other gods could come up with an argument stating otherwise. He called a meeting amongst his most trusted siblings and children on Mount Olympus, and established a small circle of gods and goddesses who would be revered almost as highly as Zeus was, to be known later as the Olympian gods. It was at this meeting where the Great Pact was formed; Zeus didn't want another uprising of the gods.
The last thing he wanted was to be slain the way his father was, and so, his solution was to make it law that no god or goddess could kill one another. In that way, the hierarchy would be set. There were many gods who were against his idea, but as much as they protested, his word was law. Fortunately, there was one goddess who discovered the loophole in Zeus' decree.
As the gods divided the domains amongst themselves, and the number of gods grew, the loyal titan, Prometheus, was busy at work creating humans from water, earth, and wind. It was a time of growth and prosperity on earth, as it was being rejuvenated and recreated from the Titan War. Prometheus created the humans in a systematic matter, first artistically creating their mud forms, and then breathing life into them all at once. Because Athena was Zeus' most trusted, favored, not to mention intelligent daughter, she knew of Zeus' plans beforehand, and told Prometheus to delay his final step until after the meeting. That way, Zeus' law would only apply to the gods.
But when Zeus saw god-like the humans looked, Zeus became worried. There were too many of them to instill another decree, and when they gained the gift of fire, he saw how powerful they could potentially become. He became infuriated at this realization, and punished Prometheus. Zeus set out to create Pandora's Box, his goal to unleash terror, death, and chaos to rid of the human race. The gods were divided. Those who were loyal to Zeus toiled day and night to ensure that the box wouldn't fail at its task, and those opposed hastened to come up with a new solution. By then, they had realized that in delaying Prometheus, the mud forms of the mortals had weakened and had rendered too weak to defeat any of the deities, especially Zeus, whose anger and greed had hardened his heart and strengthened his powers. The night before the box was to be given to Pandora and Epimetheus, the minor goddess Nemesis placed Hope inside the box. The Fates had advised the 'nemesis' gods to place her inside, so that one day, a group of heroes may emerge and put an end to Zeus' tyranny. In honor of the titan who had given the gods hope, these heroes would have powers relating them to him, as well as some of their own.
Eons had passed and great heroes such as Heracles, Achilles, Perseus, Jason, and Odysseus came and went. In desperation, Hope donned special abilities to all the mortals, praying that some of their gifts would flourish into godly powers, but most of the abilities remained mere talents; definitely nothing that could stand a chance against Zeus. Hope became lost and began to slowly wither away to the dead, but the gift of fire, control over wind, earth, and water, his foresight, all of these things were not to culminate into great gifts until four young people, on the day of their seventeenth spring equinox would stumble across death, and genesis would occur.