Ker

Ker (ケ ー ル, Kēru) was a Goddess servant of Hades as well as the younger sister to Hypnos and Thanatos. She presided over destinies. She has acted covertly since mythological times and is the responsible for causing countless calamities wherever she cast her misfortune. She was the real architect behind the evil that befell Gemini Saga which almost culminated in the defeat of Athena and her army in the Holy Wars of the 20th century.

Origin of Name
In Greek mythology, Ker is one of the "keres" (Greek: Κῆρες, singular Κήρ, "fatality"), female daemone spirits who personified destruction and violent death. According to Hesiod, she is one of the daughters of Nyx and like all descendants of Chaos, they are infallible

Appareance
Ker is a beautiful young woman with long dark hair whose hairstyle consists of a fringe that falls over her forehead while the rest is loose. Because of her surplice, few areas of her skin are visible, while while attire she wears a short dark leotard. Overall, Ker bore a similar resemblance to his older brothers Thanatos and Hypnos.

Personality
Ker seems to love  "playing" with people's lives at her leisure and shows no remorse for her atrocious actions, seen in the way he used Lemur to corrupt the mind of the Gemini Saga since he was born and ruin his life. Likewise, she has no regard for those who serve her, having killed a dying Lemur without hesitation for failing to fulfill her goal of killing Athena

She is a goddess proud of her divine position. She seems to greatly respect her older brothers, Thanatos and Hypnos, referring to them honorably. Remarkably, Like Thanatos, Ker firmly believes that human existence has no value and only serves to fulfill the desires of the gods, however, like Hypnos, she tends to act in a calm and controlled manner, being also cautious and prudent when acting in favor of favoring Hades and his army. Ker is also highly intelligent and seems to have a great understanding of morality, hating hypocrisy, seen in the smiling countenance she had shown in rebuking the false evil attitude Kanon claimed to have had before leaving him to die at Cape Sunion.

History
Ker seemed to reawaken at the time of Saga and Kanon's birth and sent an evil spirit known as a lemure to possess one of the children, looking like a split personality, which merged with Saga. Years after this she appeared in front of Kanon imprisoned inside Cape Sounion offering to him freedom in exchange for him to kill Athena. At his hesitance to this despite having proclaimed such prior, Ker explained that it was Saga the one possessed by the evil spirit and Kanon's claims of being evil were merely a way of acting out against his brother's superiority. Soon after she stopped Saga to commit suicide after the presumed death of Athena, telling him she would not allow him to die until he had fulfilled his mission of killing Athena.

13 years later, just after the end of the battle at the Sanctuary, Ker observed from outside the outcome of the battle and when the killed the lemure previously merged with Saga after it was expelled by the light of Athena's shield, noting that Hades' army had soldified its superiority from the deaths of many Saints through the conflict. Kanon, having sensed the death of the brother, suddenly appeared and attacked her with the Poseidon's trident. She managed to defeat Kanon but decided to spare his life hoping for a war between Athena and Poseidon.

Origin
Ker appeared only in the short stories Saint Seiya: Origin and Saint Seiya: Destiny that told the youth of Saga and Kanon, as well as the events surrounding Kanon just prior to the Poseidon Arc. She is based on a singular version of the Keres, death spirits from Greek mythology drawn to deaths on the battlefield who do not have the power to kill directly. Like Ker, the Keres were siblings of Thanatos and Hypnos due to being the daughters of Nyx.