Come on, Smash Bros. 4! Shantae vs Mario vs Sonic vs Mega Man? Yes Please!
A fan dream, right?
Deal!
If you want Shantae to crossover with a SEGA franchise, make it Sonic the Hedgehog X Shantae. Oh, and Kirby X Ristar.
How about... Shantae X Street Fighter 2 YEAH!!!!
Unlikely on a short-term basis, but if Capcom goes bankrupt there's no telling where their IPs will be after, so you never can tell.
That Seems like a Good Idea I must admit.