Silver did not come to Earth to be a hero. His real name is Trissan Daan, and he is an alien known as a Nayrees. Nayrees are silicon-based lifeforms, sentient androids, native to the Andromeda Galaxy. Trissan is a Warden for the Precis Alliance, which function roughly similar to a United States Marshall. Wardens handle security for Alliance officials, protection of witnesses during Adjudication, and the tracking and retrieval of escaped prisoners. This last duty was the reason Trissan was passing through Earth orbit when the Qularr launched their invasion.
Daan was hunting an escaped scientist known as Dr. Mechan. Mechan was a radical scientist convicted of Crimes against Sentience for performing illegal and torturous experiments on hundreds of non-organic sentients. He had tracked Mechan to the Sol system where the scientist was hiding on the darkside of Earth’s moon. Mechan’s ship bolted from its orbit when Daan entered normal space and was lining up for a jump when the Qularr invasion fleet appeared. The Andromedan ships were assumed to be hostile and fired on by the Qularr, severely damaging both and forcing them to attempt emergency landings on the planet.
Daan landed in Millennium City and suffered only minor injuries, but his ship was completely unsalvageable. Even temporarily stranded, Daan’s first priority was to find and capture Mechan, but he could not ignore the Earthers plight during the Qularr attack on Millennium City, so he helped with the defense. The recognition Daan received for his heroics gave him the idea of becoming the Earth hero, Silver Hunter, both as a way to draw Mechan out of hiding and as a way to develop contacts and resources to assist in hunting the escaped scientist.
Mechan was less lucky and skillful in his landing. He was severely injured in the crash, his legs and arms crushed and most of his major organs damaged. He would have died except the automated systems he had rigged to conduct experiments while he fled Precis controlled space survived mostly intact. These automations allowed Mechan to rebuild his body with synthetic parts; his pathological obsession with artificial and non-biological life culminating in his transformation into the synthetic being known as Necromechan.
Since the defeat of the Qularr invasion, the Silver Hunter and Necromechan have met and fought several times. Each time, the battles have ended with Silver frustrating Necromechan’s plans and the villain either escaped or captured. Unfortunately for Silver Hunter, Necromechan always seems capable of escaping incarceration. By Precis law, Warden Daan must either be certain that Necromechan is permanently incarcerated or get permission to take him back to the Precis prison world before he can return home, so for now the Silver Hunter will remain a hero of Earth.