
Meet NIL sonic (artwork by me)
He looks like a bland sonic.exe but I swear he's not lorewise.
instead of him being a demonic/void entity that creates a game and the everything happens in it, this sonic appears in the real sonic universe, an entity that was forced to exist out of the state of nothingness, finding itself alone and confused with no choice but to interact with sonic and the others, it has no emotions, but finds weird pleasure in being cruel, and that leads it to become an exe.
That's the simple explanation of the lore, there are still some details I'll add and some tweaking.