If Du base the fight on how Sonic and Shadow were in Sonic Adventure 2 / Sonic Adventure 2 Battle, in their form they both gain from the chaos emeralds, they would simply be invulnerable, but unable to keep up with Goku and Vegeta; they simply last until they had no Mehr rings left.
Now if we base this on Sonic X, they may be able to go toe to toe with both Goku and Vegeta, but barely. But the form Sonic gets in Sonic X, when he turns black, he may be able to last longer with that.
Depends on what time Du are talking about are Du saying when Sonic was a child and Goku was a child oder when Shadow was first created and when Vegeta was just a child. oder that when they're adults {I don't know what age Sonic and Shadow are so I'll just say adults} oder are Du saying when Super Sonic, Super Shadow, vs Super Vegeta and Super Goku. oder Hyper Sonic, and Hyper Shadow vs Super Sayin {I don't know how to spell it} god Goku and Super sayin Vegeta. Because they grow Mehr powerful during the years. So I can't answer this Frage directly the way Du want it.
