If Silver can be taken to be in his mid-teens, like in the games, he was born around 55 years into Mobius' future, to as-yet unknown parents. With the world ravaged by Super Sonic, whom the people know as Iblis, Silver joined G.U.N.'s battle against the demon as soon as he was old and strong enough to fight. After several years of fighting but never defeating Iblis, Silver grew weary of fighting and was willing to end the battle by any means necessary, including time travel. After retrieving the three remaining Chaos Emeralds and the now ancient Knuckles from the Floating Island, the time portal was activated, just as Iblis launched an early attack. As a massive explosion erupted behind him, signifying the loss of Knuckles and his friends, Silver and his portable intel device, A.G., began their journey 70 years back in time, to a point where Iblis was relatively weak.
Upon his arrival, Silver was moved to tears by Mobius' former beauty. He almost immediately after met Tails and The Ultimax and was awestruck, having grown up hearing stories of the new Hero of Mobius. There are gaps in Silver's history though: In all the stories Silver had been told, there was no mention of Sonic the Hedgehog. Indeed, Tails had replaced Sonic in all the stories. Silver worried that he had altered history simply by travelling back in time, until he learned that the creature he knows as Iblis is actually Super Sonic. Deciding that Sonic was the source of the future's misery, Silver downloaded all data on the fallen hero and his most recent sightings to A.G., and set off for South Island, intending to kill Sonic, leaving Tails and the Ultimax with a real predicament: How to protect Sonic without being seen helping a known fugitive.