How the world came? Chaos, the deity of windswept nothingness, Nyx, the goddess of the night, Erebus, the god of unending darkness, and Tartarus, the god of the underworld’s darkest realm and the abyss, were the only gods in the beginning. Nyx, the goddess of the darkness, deposited a golden egg in the shape of a big black bird and perched on it for a long time in form of a bird.
Finally, life began inside the egg, and as it exploded, Eros, the god of love, emerged. The sky was formed by one half of the eggshell rising above, while the earth was formed by the other half falling downwards.

The union of Eros and Chaos produced birds, the first living entities that predate even the gods. Because Eros and Chaos are both winged, the birds are also winged and able to fly.
Then, starting with Uranus and Gaia, and all the other gods, Eros gathered all the essential components to create the Immortals. The gods eventually produced mankind, and the world was complete. see How the world came