Aristaios rose to be considered one of the Champions of Boeotia due to his skills as a soldier and a tactician. His generation of the champions also included Deianeira, who became a central figure of the group. She was a member of the Heroes of the Cult branch of the Cult of Kosmos, and under her influence, the Champions changed.
When the Spartan army marched into Boeotia in order to weaken Kleon's position in Athens, the polemarch Stentor, received reports revealing Aristaios' location. Before he could use this information otherwise, his step-sister the misthios Kassandra came to the Spartan Military Camp by the order of King Archidamos. Wishing to be rid of her, Stentor tasked her to kill the Boeotian champions, including Aristaios, believing such a mission to be her death.
- If Nikolaos is slain in The Wolf of Sparta, then he won't be there, fighting Aristaios, of course.