When Prince Adam travels to the Skeletor-dominated future in search for the Power Sword, he is taken prisoner and meets Andras as another prisoner. When Adam escapes, he finds Andras escaping too, and they take a ship to go with the resistance led by Adam's future self. There, it's revealed that Andras is Duncan's successor as Man-At-Arms when he dons a similar armor.
Future Adam tells Andras to remain behind for the final batle as a favor for his late mother, which together with Andras' name, implies that he's the son of Lieutenant Andra. After both Adams get the sword and each becomes He-Man, future He-Man remains in the crumbling Grayskull to defeat Skeletor once for all. Andras is shocked of hearing this from "our" He-Man, but soon he helps the newly-raised Eternian forces against the remaining Evil Warriors.