Alchemist Prime is one of the Thirteen and is the co-founder of the early Cybertronian civilization with Alpha Trion, while the other Primes separated across space and time after their great schism.
He was among the Thirteen created by Primus to battle and defeat Unicron and witnessed the activation of the Well of Allsparks. According to Alpha Trion (Transformers: Exiles), after seeing Cybertron set on the path to civilization, he departed in pursuit of the Liege Maximo in order to imprison him for his crimes. Though he never saw his brother again, Alpha Trion felt that he had been successful. However, another source (The Covenant of Primus) indicates that Maximo died on Cybertron, thus leaving Alchemist's fate an even greater mystery.