Two different versions of the fastest thing alive are here to duke it out!
Scourge is the version of Sonic the Hedgehog from Anti-Mobius (aka Moebius). Scourge is an exact equal and opposite of Sonic in nearly all aspects, especially in terms of personality. Scourge mistreats others, is selfish and greedy, and has a great desire for power. Originally, Scourge, like all other alternate versions of Sonic, looked identical to him, differing only in personality and attire. All this changed when Scourge, in a failed attempt to steal the Master Emerald with Rouge the Bat, tried the Emerald's power to go Super but was interrupted by Locke half-way through the transformation and was permanently changed.
Silver Sonic II was a scaled-down version of Silver Sonic. After the defeat of Perfect Chaos in Station Square, Eggman unleashed Silver Sonic II to attack the vulnerable city. The robot's power proved to be too much for most of the Freedom Fighters, but he was defeated by Sonic, who knocked his head off. He was then reprogrammed and repaired by Nate Morgan to act as the city's defender against Eggman and outside forces of evil.
Two different Sonics, which one is the best?
Silver Sonic II and Scourge were just about to call it tie until Scourge came up and didn't quit! Scourge wins the round!