From Collin de Plancy's Dictionnaire Infernal
In Christian demonology, Alastor (from Greek: Ἑλέστωρ – "avenger") is chief executioner to the monarch of Jinnestan.
Rank[]
According to Dictionnaire Infernal - Collin de Plancy (1863), Alastor is likened to Nemesis and the destroying angel and is known as The Executioner. He is exceptionally cruel.
History/Beliefs[]
Alastor ("avenger") in Greek mythology, was the personification of familial feuds. He was also associated with sins that pass down from parent to child. As a genius, or spirit of the household in Roman mythology, he incited people to murder and other sins. The name became a generic term for a class of evil spirits.
Plutarch says that Cicero hated Augustus so much that he conceived of a plan to kill himself outside Augustus' foyer, in order to become his alastor.
Sometimes he resolved to go into Cæsar's house privately, and there kill himself upon the altar of his household gods, to bring divine vengeance upon him; but the fear of torture put him off this course. verse 68 of Cicero's bio in Plutarch's Parallel Lives*Another Alastor was a mortal, son of Neleus, King of Pylos. He was later downgraded to a minor daemon after he and his brothers were killed by Heracles.
Last but no least, Alastor was friend of Serpedon, who was killed by Odysseus.
Percy Bysshe Shelly wrote a poem (Alastor or The Spirit of Solitude - 1816), which warned idealists that if they are always searching for an ideal love, the world will be their tormentor, and they will die a lonely death.
Edward Alexander Crowley, 20th century ceremonial magician, changed his first name to Aleister. The difference in spelling can be easily attributed to the fact that 'Alastor Crowley' does not add up to 666.