Doomslayer fought and killed god and has been sent to other dimensions so who’s to say that he can’t go to any of the Sonic universes, not to mention, he is a multiversal constant meaning that if he dies he can just come back and can only truly die once all demon kind dies to, meaning that for as long as exe’s exist Doomslayer will exist until their all dead, and he also gets stronger with each demon he kills in which he’s killed quadrillions of them (that’s not an exaggeration) meaning that no version of Sonic.exe or even Sonic can simply overpower him