Each of today's entries were the black sheep of their families. Each a shadowy reflection of the the Green Lanterns of parallel planets.
William Hand was the sole son of a prominent family that turned to crime instead of reputable pursuits like his brother. He was known for a book of cliches to aid him in any situation, supposedly. As the Black Hand, William developed an energy absorbing rod that absorbed the Earth-One Green Lantern's residual emerald energy, and began a recurring series of duels against him.
Captain Kortz was a German officer and spymaster during World War II who continued to have clashes versus the Green Lantern of Earth-Two and his "Legion of the Lantern" which were fellow soldier's of his foes' alter ego of Alan Scott. At one point, in order to infiltrate nomadic society, Kortz donned a black robe and became the nefarious Black Prophet in order to foment schemes. However, Lantern continues to defeat Kortz and after several clashes he was apparently apprehended for good.