Earth-Man is a xenophobic tyrant with the ability to siphon the powers of others. Former enemy of the Legion of Super-Heroes, he now was coerced into joining them.
Kirt Niedrigh first appeared trying out for membership in the Legion of Super-Heroes. Calling himself Absorbancy Boy, and possessing the ability to absorb the energy residue of any super-powered being, gaining their powers himself, he was rejected on the grounds that his powers were too limited.
Incensed at his rejection, Niedrigh found the costume of "Zoras", a fake villain used as a final test for new Legionnaires. Attacking the Legion and defeating them, Niedrigh revealed himself, believing that he had earned his place on the team. The Legion did not see things this way, and Superboy attempted to confiscate the suit. Niedrigh used the suit to project red sun radiation, and, absorbing Superboy's powers, was able to defeat the Kryptonian. Niedrigh was then defeated by the Legion's new member Tyroc, who used an ultrasonic scream to blister his newly-acquired superhearing.
Years later, after the Dominator's had secretly taken over Earth and disbanded the Legion, Kirt's name appeared on a list of Dominator test subjects.
However, during an archaeological expedition in the Arctic, a crystal tablet was found. The tablet said that Superman was not from the planet Krypton, but from Earth, and protected Earth from aliens. Absorbency Boy, now called Earth-Man, spread the "true origin" of Superman further, and made Earth secede from the United Planets and ban all aliens. Earth-Man formed his own team of super-powered Earthlings called the Justice League of Earth to hunt down aliens and place them in camps.
Earth-Man and the rest of the JLE appear as members of the new Legion of Super-Villains in Final Crisis: Legion of 3 Worlds. He states that the alliance is only temporary, since the villains all want the same thing: death to the Legion.
Joining The Legion
Following the defeat of the combined JLE-LSV, Earth-Man is again imprisoned, until the Earth Government, eager to mollify his pro-human supporters, forces the Legion to offer him membership in return for allowing the Legion to remain on Earth. While mulling over their offer, however, Earth-Man is also offered a Green Lantern ring by Dyogene, a creature from within the planet Oa.
Powers and Abilities
Power Absorption: Earth-Man has the ability to absorb and duplicate the superpowers of Metahumans and aliens. However he is not able to copy the knowledge or skills, so it will normally take time for him to master a new power. He absorbs energies of people within a certain range of him; anywhere from several feet to a mile radius. He has shown the capacity to manifest numerous powers at the same time.
Earth-Man occasionally shows difficulty in juggling multiple powers, and his body can be overloaded by absorbing too many at once. Usually the Earth-Man loses his duplicated abilities once out of range of the owner, but theoretically due to the length of time spent with them.