The first Kid Supreme was Charles Flanders, a boy who could tap into Supreme's powers. He became Kid Supreme, Supreme's World War 2 sidekick, though his relationship with Supreme was not one of equal partners – rather, Flanders was more of a pet than a friend to Supreme.
Charles Flanders's Kid Supreme were removed from existence after the Supreme continuity was rebooted by Alan Moore, though he still exists in the Supremacy.