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.
Every child, woman or man
Opinion don't matter, stick to your plan
If they judge, still don't budge
Don't give an inch, don't give a nudge
Life's a bitch, leave you battered and bent
Lose or win, gotta hold up your chin