I would like to see how a third, and maybe final rematch between Mario and Sonic go after the Bowser vs. Eggman fight. Now, I know Eggman lost, but he and Bowser had their armies, and Mario and Sonic don't have any, not any that could be used for their possible next fight. Now...
I'd say the Power Star warping Mario across the universe, over 40 quadrillion times faster than light, is impressive and all, but that is nothing compared to the 73 quadrillion times faster than light feat Solaris had. Sure, it is unknown if Sonic actually could keep up with that even in his super form, but nonetheless, that is impressive. Plus, Sonic has Chaos Emeralds. Mario has had to collect the more numerous Power Stars that had similar power, but nonetheless, he used them less frequently and probably has less experience using them compared to Bowser, who is a different opponent and character altogether, if I recall correctly. Still, I think Mario doesn't use the Power Stars like Bowser, nor does he use much magic as Bowser does other than those Power-Ups. Sure, Mario and Sonic have had to deal with Bowser's might and Eggman's machines respectively, but I don't think Mario has immunity to magic, well, neither does Sonic, but he has probably been hurt by the magic Bowser's army has had. Sonic, in or out of his super form, which scales above the Paradox Prism and Time Eater as a mini box said during Eggman's rundown, by the way, has dealt with Eggman's machines and all, and while they needed power sources that may not have always been available (which is partly why Eggman lost), he still fought them, so his experience with them may make Eggman not readily having his power resources available not be too much of a deterrent.
I do realize that Mario is still cartoony and all, but I do think Sonic has a chance, even though I would still bet Mario. Plus, both black holes they had (Mario Galaxy and Sonic Colors), they were saved from those black holes, and while Bowser probably could survive it, Mario isn't anything like Bowser; so he would probably need saving from that black hole like Sonic did when the Wisps saved him at the end of Sonic Colors.
I welcome all counterpoints. Anyone have any? I would like to know.