As long as Sonic is ostensibly a multi-platform character I don't want them to add anymore characters from his franchise but him as anything other than trophies and assists. If they want to add another Sega rep that's fine (and they have, although Bayo's pretty much a Nintendo character at this point), and there are plenty of avenues to take but I cannot in good conscience start wishlisting for Sonic characters to fill up roster spots.
No, not even him.
Oh, why must I tell 'em again?
What must I tell 'em, my friend?
That we are born into sin
And we are worshiping murderers
Nothing but evil duplicitous men
I know you heard of 'em all
We should just murder 'em all
We should just murder and ball
We dance on the ruins we looting from all of they palace's walls