Neleus was born as the son of one of Barnabas' brothers. At some point, he begun to pursue a career as an athlete, aiming to become an Olympian, and Mikkos was appointed as his caretaker.
While training at the Champion's Gymnasium in Thasos City, Neleus befriended Aietes, another hopeful athlete. They enjoyed each others company, despite their rivalry, both in and out of training, and often spent the night at Karpos' House, drinking wine. One such night, however, Neleus partook of wine that had been tampered with.
In Tough Love, if the Eagle Bearer urges Barnabas to be less harsh on Neleus upon finding him sick, Barnabas will ask the crew to check up on him at the end of the "Have You Seen My Mikkos?" questline. If not, Barnabas will not, leading to Neleus' death within the burning house during the Retribution mission.