I feel like Mario + JRPG is more chocolate + peanut butter and Zelda + JRPG is chocolate + another chocolate, based on the general settings and trappings of a lot of JRPGs. Metroid or Kirby would be more interesting to me off of how the mechanics and settings could mix more. Donkey Kong RPG could be fun/funny.
I do wonder if a Nintendo crossover RPG might be something we’d benefit from. It could kind of soothe some people’s calls for Smash to have a new story mode.
I didn’t talk about third party characters earlier, so I might as well throw my cents into this ring. Also not I’m hesitant to give a certain third party company many more characters than the others, so three seems to be my personal cap. The real chances will likely look more all over the place to be honest.
The Big Three:
I think Smash can’t go without these guys now, unless we bring the roster down to below Brawl’s count (39). Sonic and Street Fighter have always been popular and have been making strides recently. I think these two have tons of room to bring in new faces, stages, music, and more. Also the Pac is back.
Safe(-ish) Secondary Choices:
These guys I see little reason to cut besides unavoidable issues, such as age ratings being an issue. Many legacy fans may seethe at me placing Ryu as higher priority to Mega Man, but that’s just how the state of Capcom seems. Kazuya I see little reason to cut. Bayonetta and/or Joker would be more safe if the ESRB was not an issue. Terry’s a bit of a wild card, fluctuating between these two tiers due to Kazuya and Ryu also being safe picks.
Harder to Secure Primary Faces:
These guys might be harder to deal with, likely due to company stinginess, or just being expendable enough to leave out next game. Cloud and Hero fall into the earlier point, while Simon and Steve, both popular additions, may fall into the latter tier of being crammed by a smaller roster.
Secondary Faces who need EIH:
I think these guys will be the first to go. Snake has the double whammy of being M-rated putting him at risk until we learn more, and Konami not being in Smash 4. Banjo had a lot of fan-demand, but I think he might not return in favour of say, Crash. And Sephiroth likely won’t return if Cloud comes back with more content, and I don’t see Square Enix getting what basically amounts to being a whole Fighter’s Pass to itself. These are the characters I’m least confident will return.