Supermen of the 30th Century

In the year 2965, Klar Ken T5477 was a journalist at the Daily Interplanetary News, but secretly the Superman of his era and descendant of the original Man of Steel on Earth-One. His love interest was Lyla 3916 and his pal was Jay L 3388 while his arch enemy was the mutated villian known as the mental  mutant Muto. Although not vulwenable ro Kryptonite like his famous ancestor, due this to radioactivity from nuclear weaponry contaminating the seas, Klar is adversely affected by sea water. After three chronicled solo tales, Superman worked alongside the Batman aka Bron Wayn E7705 from his time period versus Muto and the futuristic Joker. Following this victory, no further tales were published about him.

In the year 2956, journalist Craig King for the Daily Solar System and a coworker of Lyra Lee and Parri. Craig was selected by a groups of scientists to become their era's Superman. Equipped by futuristic devices allowing him to fly via jet pack, move heavy objects with gravity displacement, and be nigh invilnerable thanks to a special fabric in his costume... this Superman was tasked to face felons that started to appear. When he proved unable to meet this objective, King communicated with the original Superman in the 1950's. 

This Superman was shocked that he could be contacted by individuals from a thousand years in the future, which the Earth-One Superman would not because when he was Superboy he was a member of the 30th century Legion of Super-Heroes. Also, Kal-L was amazed at how Metroplis looked in that far flung future era, which Kal-El would not have been as he was a frequent visitor. Hence, the golden age Superman subbed for Craig and saved the day by apprehending the criminals born ten centuries from now.