the 30th century of Earth-One, capable of each transforming into near indestructible iron, which greatly increased their strength. Andrew joined the Legion of Super-Heroes, although shortly thereafter he perished protecting the galaxy from the sun-eater which threatened it. This left Douglas to carry on the legacy his brother had carved out for the Nolan name. On Earth-Two, during the middle of the 19th century during the conflict known as the Civil War, twins Billy Yank and Johnny Reb fought against one another and had a series of adventures, mostly separate but occasionally interacting with one another. While both were on opposite sides of the conflict, they still each attempted to be heroes from the individual perceptions. When they died, their legacy then passed on to Sam, and presumably like him they each possessed a measure of superstrength and invulnerability for a limited period of time.
Then there was Roger Romaine of the east coast of the of United States and his same-named cousin of the west coast. Of course, there was also Albert and Alvin Desmond, distant cousins who had a mental connection also living on different coasts. These cosmic twins are different than those previously considered, as we shall see.
Next, let's consider Albert Desmond, whose criminal tendencies motivated his scientific acumen towards a career as the costumed criminal known as Mister Element, a crime spree abbreviated due to the appearance of Earth-One's Flash. So in response, he adopted a new alias as Doctor Alchemy, possessing the transmuting Philosopher's Stone... and still met with failure. Eventually, Desmond joined the Crime Champions where he encountered his foe and another Flash as well as their twin teams. After a series of failed attempted at fame, Albert retired from crime to reform and marry his girlfriend Rita. Soon thereafter, Albert's cousin Alvin assumed the alias Doctor Alchemy which led to a duel between the two, with Alvin eventually joining the second incarnation of the Crime Champions then fading away. Albert's counterpart on Earth-Two, Mister Alpha, didn't have a twin himself, instead Alvin's counterpart was a red haired man like himself named Slicer who had attempted to obtain the Philosopher's Stone of his world from the evil Lorelei, rather unsuccessfully as it turned out (Lorelei and her allies Rumpelstiltskin and Gallifron were the dopplegangers in an Earth-Two adjacent dimension to the trio of terror Saturna, Simon Magus, and Troll King of an Earth-One adjacent dimension... each foes of the Justice Society and League respectively).
These unique cases show that cosmic twins aren't simply a feature of parallel planets, but even two similar sets on the same Earth at times!