Acheron Parthenopaeus is a member of the Atlantean pantheon, one of the last of the Chthonians, and the leader of the Dark-Hunters. His reputation for vagueness and never answering any personal questions is legendary. Acheron first appears in New Orleans in Night Pleasures to aid Kyrian and Amanda Devereaux in regaining Kyrian's soul so that Kyrian could vanquish Desiderius.
Ash has strengths and vulnerabilities unknown to anyone but himself and a few others. Almost no one is quite sure of his true age and lineage. He is more powerful than regular Dark-Hunters and one of the most powerful beings in existence. Like others, he's a Source god which means he can tap into and wield the power of the primal Source. However, he is really powerful even without it. Like Sin, his son-in-law, he fights to protect and defend humanity and the innocent in general against those who would see the innocent destroyed.
The king and queen of the Atlantean gods, Archon and Apollymi, were due to have a child. However, the three Greek Fates, daughters of the Greek goddess Themis and result of Archon's infidelity to Apollymi, came to their father, holding hands, and, afraid that their new half-brother Apostolos would deprive them of their father's affections, spoke that Apostolos would be the death of the Atlantean pantheon. No sooner had the prophecy been uttered than almost every other Atlantean god demanded the death of the unborn baby.
Unwilling to sacrifice her baby, Apollymi fled to her birth home of Kalosis, the Atlantean hell realm, where she knew the others wouldn't follow, with her niece Basi and her Charonte demons. Apollymi cut Apostolos out of her stomach, extracted his godhood, and had Basi place him in the womb of a pregnant queen, merging Apostolos's life force with that of the human queen's child, ensuring Apostolos's safety.
The queen chosen was Queen Aara of Didymos. She gave birth to Apostolos and another son as twins. However, when his human mother saw his eyes, which were of a swirling mercurial color, an oracle came forward, declaring that Apostolos would be the death of them all: "His touch will bring death to many. Not even the gods themselves will be safe from his wrath." She then informed them of the twins' connected life forces. King Xerxes accused Aara of being unfaithful. When both his mother and father refused to acknowledge him, the oracle named him "Acheron" for the river of the underworld representing sorrow.
Then he shall be named Acheron, for the river of woe. Like the river of the Underworld, his journey will be long, dark, and enduring. He will be able to give life and to take it. He will travel through life alone and abandoned, ever seeking kindness and ever finding cruelty. May the gods have mercy on you, little one. No one else ever will.
At the age of seven, Acheron was ripped from the arms of his sister Ryssa and taken against his will to Atlantis, where he was to be left in the care of his uncle Estes. From then on, he was trained as a tsoulus, a sex slave, and was abused mentally, physically, and sexually for nine years, being starved for weeks at a time and beaten severely for minor offenses such as speaking out of turn.
In the winter of his sixteenth year, Ryssa received a letter from an attendant of Acheron asking her to come to the aid of her brother. Ryssa, wanting nothing more than her brother's safety, discovered that her uncle was selling Acheron and took him away to her summer palace. For many months, they hid from their father and uncle while Ryssa and a small servant child named Maia coaxed Acheron out of his shell. When he had finally begun to trust in Ryssa, his father discovered them and sent him back to Atlantis to be sold by his uncle yet again.
Two years later, Estes died by being killed by Acheron's twin brother, Styxx, which left Acheron homeless. He worked as a prostitute in Didymos, where Ryssa found him yet again. Angry at her for showing him a better life than what he had so long ago, he sent her away. For another month or so, senators from the palace paid to sleep with Acheron to vent their frustrations with his twin brother Styxx (heir to the throne of Didymos) on him. Styxx and Icarion overheard the senators discussing Acheron and he was consequently thrown into the palace dungeon, where he was kept for several months. Ryssa freed him when he nearly died of starvation, causing Styxx to almost die with him since their life forces were connected. From then on, Acheron was kept in the palace, but confined to a single room.
Acheron and Artemis met in her temple. Artemis was the first woman he was attracted to, just as Acheron was the first man that Artemis ever wanted. They agreed to be friends (though their physical relationship indicated that they were lovers). Artemis, despite the fact that she loved him, would not look at or touch him in public, nor ever have his name tied to hers. She was ashamed that he used to be a tsoulus and feared that she would be stripped of her powers or killed once the other gods, especially her twin brother Apollo, learned about her relationship with Ash. This would be especially humiliating because she is the goddess of chastity. When she discovered that he was a Chthonian, she decided to put an end to his life, fearing the destruction of her family's pantheon. She drugged him but did not have the strength to kill him because of her feelings; she resolved to let someone else do what she could not. That night, due to Acheron's drugged stupor, he was not able to save Ryssa and Apollodorus from attackers.
Then the very next day Artemis watched as Apollo gutted Acheron because of his anger for his mistress and son's brutal murder. The Fates told Artemis to bring Ash back from the dead to prevent the wrath of Apollymi from destroying them all. Among them, only Artemis had the power to bring him back because she had his blood in her. She tricked him into drinking her blood, thus resurrecting him. Acheron was now dependent on Artemis, needing her blood to retain his sanity and compassion. Acheron was still mad at her and never wanted to speak to her again despite her constant pleas.
It was later revealed that Artemis bore him a daughter but Ash did not know her until she was an adult because he and Artemis weren't on speaking terms until it was too late. After two thousand years, Artemis created the Dark-Hunters in order to gain Acheron's attention, using his compassion against him. She forced him to barter with her for their pay and freedom. She had sex with him and beat him so she felt more powerful, punishing him because she could never forgive him for making her vulnerable. Artemis always made it a habit to remind Acheron of what he was and where he came from. Acheron served Artemis for over eleven thousand years until he met Tory and she changed everything. He also found out that his brother, Styxx, had gone through a similar hell as his. They then truly become brothers.
Savitar and Takeshi trained him how to manage and utilize his god powers. They also taught him how to fight. One important lesson Ash learned from Savitar is that changing one's person future, even for a positive reason, can have negative effects on many other people.
He wrote the Dark Hunter's creed and guides them in their fight against Stryker and his Daimons; he fights the gallu with Sin as well. He helps the Dark-Hunters get their souls back from Artemis. He also sees things before they happen so he knows when the Dark-Hunters need help.
Katra Agrotera is a kori (handmaiden) for his mother Apollymi in Kalosis. She originally served both Artemis and Apollymi, but her service was traded to Apollymi in exchange for saving Ash from Desiderius. She is also Acheron's daughter that he fathered with the Greek goddess Artemis.
Nick Gautier was his best friend until he slept with Simi. In a fit of rage, Ash cursed Nick to kill himself. On the same day, Nick's mother, Cherise Gautier, was brutally murdered. Nick hates Acheron for not using his powers to bring her back to life and views him as his worst enemy. Artemis brought him back to life as a Dark-Hunter, but Acheron has Nick's soul and is trying to train him.
Styxx of Didymos is Ash's twin brother. He, like his twin, is a Chthonian—a creature able to kill any god without damaging the Source, but he only got his powers recently. His relationship with his twin was not always good; in fact, they hated each other. Due to their horrible miscommunication with each other, Acheron thought Styxx had a perfect life growing up, while Styxx got his fair share of misery trying to save Acheron and fight off the god Apollo. Following Styxx, they have forgiven each other and embraced their brotherly bond.
Soteria "Tory" Kafieri, aided by Simi, found Ryssa's journal while searching for the ruins of Atlantis. Ash attempted to make Tory forfeit the journal, but Tory convinced him to teach her Atlantean. Tory was disgusted when a friend of Ash's told her, half-jokingly, to offer to sleep with him. He then realized that she is one of the few immune to the curse of being touched by the hand of Desire (which causes everyone past puberty to want to sleep with him) and tried to befriend her. One night, he got drunk on Sprite and told her all his secrets. She accepted him completely and they fell in love, which made Artemis furious. She manipulated Acheron into killing Tory, but Apollymi brought her back to life by transferring some of her powers to the mortal woman. Now Tory is an immortal goddess.
Ash is usually seen as a very calm and reserved individual, rarely revealing any personal details about himself and needing to keep his emotions in check. He doesn't like his hair being pulled or people breathing down his neck, as it reminds him of his time as a tsoulus. He is considered a poster child for the goth movement and has a vast collection of guitars.
- Charonte Powers: Ash possesses all powers of the Charonte demons. He was conceived when his mother was bound to Xiamara, and the demonic part of Apollymi (Braith) or his true father allows him immunity to other demons and his true Harbinger blue form.
- Final Fate: Ash can alter destiny with a single word, as shown when he accidentally told Nick to kill himself, leading to Nick's suicide. He can see into the future except for those whom he is close to. His words are law to all beings.
- Godkiller: Ash is one of the Chthonians, so he can kill other gods without releasing their power unchecked into the universe, which could destroy it. This power was never meant to be given to a god. When Apollymi put Acheron in the Dydimos' queen's womb, Acheron absorbed Styxx's active Chthonian powers and became the only Chthonian god hybrid in existence.
- God powers: Ash has all the powers you would expect from a god, such as immortality and the ability to fire god bolts. Ash can also read or erase memories, thoughts, events, and even time from others' minds. He can sense the presence of others, disintegrate into nothing, and bend the physics of time and matter. He is omnipotent and omniscient.
- Harbinger powers: As the son of the Destroyer, Ash has all the powers of a God of Destruction. His destructive powers were immense even without the added Chthonian powers.
- Immunity: Due to his Chthonian powers he is somewhat immune to an Atlantean dagger (which would kill any other god in his pantheon). The dagger only makes him lose control and go on a rampage.
- Life Creation/Destruction: He is one of few gods with the power to create life and destroy it. He is the Final Fate, thus he has both creation powers (used by Artemis to create Dark Hunters) and destroyer powers (Harbinger powers) plus his Chthonian powers and being a Source God, making him one of the most powerful beings in creation.
- Omnipotence & Omniscience: Acheron is one of the few gods with nigh-omnipotence, and as a god of fate (and the Final Fate), his omnipotence and omniscience are nearly absolute with the apparent limits of Source laws to protect the balance of the universe and the Source.
- Sex appeal: Ash is also supernaturally seductive and is the embodiment of perfect male beauty. At the height of his sexual prowess and attractiveness, he possesses raw, unearthly magnetism. It is the curse of Epithymia when she touched his skin with her bare hand when he was a baby. This is also the reason Acheron was horribly sexually abused by many in his past and even Artemis over the centuries.
- Source Powers: Acheron is a Source god, chosen by the Source to wield the primordial power and be a fundamental force of the cosmos, a Chthonian, and the Final Fate. He can sense when the balance of the universe is altered.
- Atlantean dagger
- Sprite: for some unknown reason, a modern soft drink has the effect of heavy alcohol due to.... plot reasons?
- Touching his back, sneaking up on him
- While he is a god of fate, he cannot see his own fate or the fates of those closest to him
- Backpack: Ash carries a backpack everywhere he goes to disguise the fact that he can summon objects out of thin air. He pretends that the object was already in the backpack.
- Staff: Ash summons this in combat. He uses his staff to use some Harbinger/Talimosin powers.
As Apostolos (his "true" form), he appears with black lips, black horns, black hair, yellow/orange eyes shot through with red, black claws, and blue skin with marbled streaks of various other shades of blue.
- Acheron owns volumes of the Hellsing, Priest, and Trinity Blood manga series.