The Eradicator
The Eradicator was an artifact from Superman's home planet of Krypton, a powerful living computer programmed with one purpose - preserve the culture of Krypton. Reduced to energy after a confrontation with Superman, the Eradicator used the near-dead body of Superman to create himself a duplicate Superman body, complete with memories. Confused by Superman's memories, the Eradicator acted as Superman as he helped the real Superman recover. The Eradicator was one of Superman's allies when Superman confronted the Cyborg Superman in the ruins of Coast City.