: Captain Toad is the last "main" series character that really stands ground as a fighter. Otherwise, we go to the spin-off king and queen of
Waaaaa and Daisy, or icons of the RPG series.. which at this point pretty much stands fully as Paper Mario as M&L killed off the only major reoccuring original character (Fawful).
: ....Yeah, no. The only characters not shared with main Mario are babies, the stork, and generic enemies.
: K. Rool, Dixie, and as a stretch Cranky.
: As I expect Wario Land to be ignored on majority, Warioware... possibly could get Ashley.
: Ganon has the most merit and credential as a newcomer. Impa & Tingle have some lesser roles but sizable support. The likes of Tetra, Ghirahim, Midna, and Skull Kid are "One Game Wonders" still.
: Bandana Dee is pretty much the only major one to add. Some dispute Magalor but.. he has one game as a villain and a lesser role in Dream Collection.
: A starter or otherwise highly promoted Pokemon from generation 7/8, hopefully grass-type to solve the missing third o the triangle. I don't see any of our 3 missing veterans to return.
: Wolf returns, ....Krystal is the only real expansion chance, in my opinion.
: Ridley is the only major candidate, with Dark Samus in second. Kraid has been shrugged off, Mother Brain... has her issues, and Sylux/Rundas are too minor.
: Stays the exact same.
: Let's focus on getting a new game, first, kiddo.
: A major protagonist from FE 15-17(?) or Anna.
(Retro): Icies return (Sma5h), otherwise, Takamaru is the most popular, but someone like ExciteBiker could be a surprise choice.
: No expansion.
: More alts out of captains, but no actual characters.
: MAYBE getting Tails or Eggman.
: Isabelle or Tom Nook... Isabelle's just growing too much in possibility and usage to not seem as more likely.
: ....Moving on.
: Staying the same.
: Honestly, I don't think anyone from X will come, with Elma being the most likely of them. I don't think we'll see a third Xenoblade game before our next Smash game.
"New" Nintendo Series for Fighters: Splatoon, Golden Sun, Rhythm Heaven, Chibi Robo being the big 4. MAYBE the Wonderful series... if we see W102 and if it does well.
(3rd Party Icons): Simon Belmont, a Final Fantasy Character, Bomberman, or Rayman
Indie Stars: Shantae, Butt-Butt aka Shovel Knight, MAYBE Yooka-Laylee.