The Birth: Some of the greatest talents; Mike Carlin, Roger Stern, George Pérez, Curt Swan, Kerry Gammill and Jerry Ordway had gathered together at the Watermark Restaurant. Jerry and Roger were in the initial stages of engineering what would become the Superman In Exile story. With Mike's guidance, ideas started being tossed back and forth across the table. It was George who expressed an eagerness to explore Superman's Kryptonian heritage...and that in turn led to the creation of "The Artifact " which was supposed to be something that had been removed from Krypton millenia before that doomed planet had exploded to kingdom come. This Artifact became what we know as "The Eradicator".
In Warworld, a planet ruled by the legendary Mongul, an old cleric had in his possession a part of the Kryptonian heritage; namely this Eradicator, a complex machine engineered by Kem-L, an anscestor of Kal-El, our Superman. If properly utilized, it would ensure that the Kryptonian society lasts as long as Krypton itself. This gizmo would ultimately bind every soul to Krypton... slowly establishling by genetic manipulation a common element in the race's genetic matrix. In a nutshell, if a Kryptonian left the planet, he would die. Conversely, if an outsider entered the planet he would not be able to survive. But Kem-L had never planned on the Eradicator itself leaving the planet.
This part of Superman's heritage was revealed to him in The Adventures Of Superman #455 (June 1989), when the cleric handed it down to him.

The Legend: Superman had been captured and brought to Warworld and under Mongul's decree he had to participate in the planet's gladitorial games. Mongul's blood would not allow him to merely watch the contest...he insisted on kicking butt personally. And that's when Superman defeated him and overthrew the ruler. The Man of Steel, badly injured, was brought to the Cleric's home on an asteriod off Warworld where he first laid eyes on the Eradictor. In welcoming his heritage, he let the essence of the artifact touch his soul, thereby igniting a mental bond between the two.
The troube started when Superman brought the Eradicator back to earth. It was responsible for temporarily mutating his friend, Jimmy Olsen into an elastic freak. It blew the bejeebers out of Clark Kent's appartment. And it caused some major complications in the life of the shape shifting Supergirl. Superman fianlly got fed up with the blasted thing and buried it deep in the Antartica. But like the unwanted cat in the old campsong, the Eradicator just kept coming back.
As part of it's programming to preserve Kryptonian heritage, it created a huge underground fortress. And then it began to seriously mess with Superman's mind, trying to make him more Kryptonian.
That was the last straw for the Man of Steel. As soon as he came to his senses, he flung the machine along with the costume it had created for him into the sun. But the Eradicator survived the thermonuclear fires of Sol and came back under human guise and tried to transform the earth into another Krypton. With help from Professor Emil Hamilton, Superman thought he destroyed the Eradicator with Mr. Z's gemstone.
Of course, it came back, but this time to preserve the legacy of Superman when the world thought he had bitten the dust after the no-win slugging match with Doomsday. And when Superman returned, it fought alongside with the Krytonian to destroy Hank Henshaw and in the process gave it's life for Kryton's last son.
Nevertheless, Star Labs helped in his total recovery and consequently Eradicator joined the Outsiders working to prevent crime.