|“||Even Tartarus had to rise from somewhere. This is the edge of the earliest darkness, which was my mother. Below lies the realm of Chaos, my father. Here, you are closer to nothingness than any mortal has ever been. Can you not feel it?||”|
Chaos (also known as Khaos or "the Gap") is the initial rudimentary mass of being, as explained by Ovid in his Metamorphoses. From "him" emerged the Protogenoi. Besides being a deity, Chaos is a shapeless void below even the depths of Tartarus, the realm embodied by one of his sons. Once someone enters Chaos, he/she becomes nothing and is dissolved by the void. This is where faded gods reside in eternal sleep.
Beginning of Creation
Chaos was the initial state of the universe before creation; a gloomy, soupy mist containing all the matter in the cosmos.
Eventually, some of Chaos' matter collected to form the Earth (Gaea), the Sky (Ouranos), the Seas (Pontos), the Infernal Pit (Tartarus), and the Mist/Darkness (Erebos). 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.
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.
While in Tartarus, Percy Jackson and Annabeth Chase confronted Akhlys at the "verge of final death, where Night meets the void below Tartarus." Annabeth reacted with surprise that "anything" was below Tartarus. Akhlys explained that even Tartarus had to rise from "somewhere". She showed the two demigods that below them they would see her mother, the earliest darkness, and her father, Chaos.
Later, while confronting Nyx and her children, Percy and Annabeth leapt through the Mansion of Night, risking tumbling into Chaos - which would have meant a true death, as their very souls would be destroyed. They managed to make it past both Chaos and the River Acheron into the heart of Tartarus, the current home of the Doors of Death.
Meg and Apollo's consciousness took a brief trip through Chaos, which Apollo shields Meg from.
Apollo and Python battle on the edge of Chaos, and Python dissolves along with Apollo.
Due to "his" position as the embodiment of the Void and creator of the Universe, Chaos is ostensibly the most powerful entity in the entire series, with unmeasurable levels power far greater than that of any being in existence, even that of any of his Protogenoi children.
- Supreme Power: As the Protogenos of the Void/Nothingness, Chaos's power is truly immeasurable, being the most powerful of the Protogenoi and thus far surpassing that of any Olympian, Giant, and Titan.
- Creation of Sentient Life-Forms: As first Protogenoi and origin of Protegenoi, Chaos created the universe and all life within it, since the other Protogenoi are the parts of the universe itself.
- Void: Chaos is believed to be so great that it is able to truly kill immortals and even erase souls from existence, possibly by permanently absorbing their essence. This is something believed to be initially impossible by all the Olympian gods, Titans and even Ouranos, the second most powerful being in existence. All faded mythical beings end up within Chaos, essentially making Chaos the "afterlife" for immortals.
- Eternity: As the first of the Protogenoi, Chaos existed even before the world began.
Akhlys (Misery, Poison)
- Chaos somehow was able to parent most Protogenoi alone despite being considered "male". However, it should be noted that in mythology, Chaos is mostly described as genderless.
- Apollo, in The Tower of Nero refers to Chaos as female.
- Its Norse counterpart would be Ginnungagap, though the latter was just seen as a place.
- Its Egyptian counterpart is Ogdoad Cosmogony, especially Nun, the androgynous primordial sea of Chaos from whom the Protogenos emerged.
- In The Kane Chronicles, Isfet is also referred to as Chaos and the Kane siblings travel to the edge of the Sea of Chaos to find Apophis' sheut. When Sadie mentions the Realm of Chaos to Annabeth Chase, she wonders if there is a connection between the Greek Chaos and the Egyptian Chaos, having great respect for Sadie given her own experiences with Chaos.
- Some myths name Chaos as the creator of Eros and Aether. However, in most myths and Riordan's series, Eros is considered to be the son of Aphrodite and Ares, while Aether is one of his grandchildren.
- In some myths Akhlys is listed as a primordial goddess born even before Chaos, rather than his daughter.