|“||Minor goddess? I was old before the Titans were born, you ignorant girl. I was old when Gaea first woke. Misery is eternal. Existence is misery. I was born of the eldest ones - of Chaos and Night.||”|
Little is known about Akhlys except that she may have been created before Chaos. However, this is contradicted by Akhlys herself in House of Hades when she says Chaos is her father.
Percy Jackson and Annabeth Chase meet Akhlys so they can hide themselves in the Death Mist to get through Tartarus. She betrays them, however, and chucks poison at the pair. Percy uses his powers over water to will the poison back to her, which causes her to flee from them. It is during this that a darker force in Percy's personality reveals itself.
Akhlys appears to Nico di Angelo in one of his dreams, saying she can not add to his misery.
Akhlys is described by Percy as having "serious self-esteem" issues, as well as an unambiguous sadist. Also, Damasen mentions Akhlys trusts nobody.
Akhlys looks like a victim of famine. She has a drippy nose, bloody red clawed cheeks that drip blood on her tattered dress, sunken eyes, stringy grey hair that is matted to her head, and large amounts of dust covering her thin body.. Akhlys appeared on the shield of Hercules as pale, emaciated, and weeping, with chattering teeth, swollen knees, long nails on her fingers, bloody cheeks, and her shoulders thickly covered with dust. She can also run relatively fast when properly motivated as she did when Percy rerouted the flow of poison and then began to choke her on her own saliva.
- Akhlys presumably has a goddess' powers, but infinitely stronger as she is one of the Protogenoi.
- Toxikinesis: As the goddess of poisons, Akhlys has absolute control and divine authority over poison.
- She has control over Death Mist.
- Some myths list Akhlys as a possible daughter of Nyx among the Keres.
- Although she is thought to be created before Chaos in, The House of Hades she states that she is his daughter. This mirrors how some Greek Creation Myths call Chaos the state before time began and a god, while others proclaim it was Chronos or Akhlys whom created Chaos or existed prior to it.