Chaos

Chaos (also known as Khaos, Kaos or "the Gap") is the initial rudimentary mass of being, as explained by Ovid in his Metamorphoses. From it emerged the Primordials. Besides being a deity, Chaos is a shapeless void below even the depths Tartarus, the realm embodied by one of its sons. Once someone enters Chaos, he/she/they becomes nothing and is dissolved by the void. This is where faded gods reside in eternal sleep.

Beginning of Creation
Before the sea and lands and sky, there was but one face of nature in the entire universe, whom they called Chaos. It was a rough and uneven mass, in which there was nothing except idle weight and the congealed, dissonant seeds of unstable things. No Titan yet gave forth his sunlight to the world, nor yet did Selene display the waxing moon, nor did an earth yet hang in surrounding air, nor had yet Amphitrite held in her embrace the far reaches of the world. The ground was unstable, the waves unswimmable, the airs lightless; no form of anything lasted, for one hindered another, and in one body cold contended with hot, wet strove against dry, soft things fought with hard things, and the weightless grappled with the weightful.

Eventually, some of Chaos' matter collected to form the Earth (Gaea), the Sky (Uranus), the Seas (Pontus), the Infernal Pit (Tartarus), and the Mist/Darkness (Erebus). Later, Night (Nyx) would also be born from Chaos in union with Tartarus. Along with Nyx, Chaos created Misery/Poison (Akhlys). In some myths, Eros also emerged from Chaos.

Hera's Punishment
After beginning an Olympian riot against her husband Zeus, Hera and the other gods were punished for their rebellion. While Apollo and Poseidon were temporarily stripped of their godly powers, Hera was given the worst punishment of all: she was chained right above the terrifying abyss of Chaos. Every day, Zeus would visit his wife with the Master Bolt and threaten to let her tumble into the void. Hephaestus could hear the wails of his mother all the way from Mount Olympus, which infuriated him, as he could not bear to hear her suffering such a harsh punishment. As a result, he finally set her free. Hera tearfully embraced him and promised to never to call​​​​ Hephaestus ugly ever again.