Rimnon of Ordo Nuntius, Aurelio's mentor
Rimnon taught Aurelio during her apprenticeship. They stayed in touch since, exchanging messages frequently. He described Aurelio as a loner who preferred the company of machines. She had no romantic interests or even close friends.
According to Rimnon, Aurelio had been first very excited and later worried about a research project she had undertaken. He didn't know any details, other than she bragged about a major breakthrough she'd soon announce.
Vlad, a Techmancer Trainee (dead at 19)
A gregarious glutton, Vlad was friends with the three Techmancers. They studied and partied together. He was especially fond of Gustav, following him everywhere. Vlad was from Lunarus, but didn't talk about his past. He got blitheringly drunk in the Ordo Voluptas graduation party. Vlad was fond of Lilith and heartbroken over Valefarion's success.
Vlad died from complications during the Ritual of the Conduit.
Xiu, a Techmancer Trainee (missing at 20)
Xiu was another fellow student, who befriended Vlad and the others. He was socially inept and completely focused on studies. Xiu had amazing mathematical talents constantly praised by his teachers. He saw numbers and their elegancy as sermons to the God-Machine.
Something went terrible wrong when Xiu was joined with the Conduit. He was taken into the Forbidden Archives and never heard of again. Investigations by Gustav and Valefarion (covertly aided by Siria) revealed he had been taken in "the Vaults of Processing Calculus".