Superman's Pal, Jimmy Olsen #72

Jimmy is taken by The Collector to the world Gion-El, which is seemingly inhabited by duplicates of him in the forms into which he has been transformed in the past. But when Jimmy realizes he is being hoaxed, the Legionnaires reveal that he has passed his initiation test and they bring him to the 30th century to officially be made an honorary member of the Legion of Super-Heroes.