-Super Mario
0% - I doubt they will add anyone, and they already added Piranha Plant. Prof. E. Gadd would be cool but I don't see him happening anytime soon considering the selection criteria that has been applied so far. I'm not considering Geno as a Mario character, so it's ininfluent in this list.
-Donkey Kong
10% - There's Dixie but we're not sure if spirits deconfirm or not yet... it got K Rool already though
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the legend of Zelda
30% - I doubt they will add one offs and the recurring characters are already all there in multiple versions. Classic Ganon would make sense but I don't see it as likely. Maybe something from Breath of the Wild 2 to promote the game? But it's a bit unlikely.
-Metroid
5% - Unless Sylux gets a massively epic super important role in Metroid Prime 4 and becomes one of the faces of the franchise from now on, I doubt he's going to become a fighter, simply because aside of some obscure cliffhangers hidden in some games, he is just a guy who appeared in a spin-off along with many others similar to him. I don't see anyone else as likely. By the way, the series already got its newcomer in Ultimate, Ridley.
-Yoshi
1% - Kamek and Baby Bros are the only options IMO. Maybe Poochy, but I see it more as assist trophy material than as a full fighter, simply because he seems too limited in what he can do. Kamek is already a stage gimmick in the NSMBU stage and you can't turn him off because it's basically the stage itself (the transition happens because of Kamek). Baby Bros are possible too and would be funny, but like for E. Gadd, I just don't see this happening.
-Kirby
80% - I may be biased, but Kirby is one of the biggest ongoing franchises of Nintendo that gets new games every 1 or 2 years, and it has got nothing in Smash since Brawl. I suspect one of the few first party characters in the second pass is a Kirby character. The problem is who. My hope is for Adeleine, obviously, but technically there are many options avaliable (unless spirits deconfirm). In 2 years the next Kirby game will be announced for sure (maybe even at this E3 or even earlier), and if it features a new character, it can even be the new character of that game.
-Star Fox
1% - Starfox has some interesting characters still not in Smash, but I doubt we'll see anyone in this pass, unless a new game with a major new character comes... but after the not so successful Star Fox Zero, I don't see this happening soon (unless Miyamoto really wants to push Star Fox at any cost). Krystal is stuck as assist trophy too.
-Pokémon
30% - It's one of those series that gets new characters each game, so it's natural to think it will recieve a newcomer... but I think Incineroar already fulfilled that, I think it's unlikely to get a new one... but not impossible, they may still want to promote a new game in 2 years from now.
-Earthbound
?% - I would say 0%, it's a dead series with 2 reps already, most characters appeared in Smash already in one way or another... but I think Sakurai really loves it, so who knows. The chances are pretty low by the way, but since they involve the unpredictability of Sakurai, I can't say for sure a precise number.
-F-Zero
0% - Dead franchise that despite having many characters, has always been skipped when it comes to newcomers. I don't see a F-Zero character in Smash anytime soon unless Nintendo releases a new game within 2 years, something that's most likely not happening.
-Ice Climber
0% - Copy-paste from F-Zero, except it has only 2 characters and they are already in.
-Fire Emblem
0% - Sakurai is aware that Smash fans are annoyed by more Fire Emblem. He even made some references to this during the presentation, before the trailer and during it (the too many swordies part). He added one already, plus 1 echo in the base game... unless he's insanely biased for real, I don't see more Fire Emblem coming in this Smash.
-Game & Watch
0% - Mr Game & Watch is enough already.
-Kid Icarus
10% - Uprising is old and there are no known plans to continue the series anytime soon. There are some possible characters, but I doubt they will be added, if Sakurai was really interested in doing it, it would have happend in Smash 4 already. But I keep this at 10% because Uprising is still a game made by Sakurai.
-Wario Ware
0% - No way. There is a fun set of crazy characters in this series, but I think Sakurai considers it already represented well enough by Wario himself, and he doesn't seem interested in adding anyone else soon.
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tactical espionage action Metal Gear Solid
?% - I'm not familiar enough with this series to leave an opinion on this. Probably not though, because he'd rather add a character from a different Konami franchise, or a character from a differetn company completely.
-Sonic the Hedgehog
15% - not likely, but with an hipotetical announcement of a new game, and the movie, the franchise is going to stay relevant for a while, so a newcomer is possible. Regardless, I think that third parties will mostly focus on getting new franchises rather than putting more reps of already represented ones.
-Pikmin
0% - Unless a new game comes and a new important character is added to the cast, someone who becomes a second face of the franchise after Olimar, I don't see this happening.
-R.O.B.
0% - dead franchise, I don't see the professor being added, R.O.B. itself is enough already.
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welcome to Animal Crossing
0% - The new game is coming, and all. But Isabelle has just been added in the base roster, and there's nothing much you can do anymore unless you add a gimmick character like Mr Resetti or K.K. Slider, which I don't see Sakurai adding as fighters (isabelle is already a semiclone of Villager). It seems that Tom Nook is not going to join smash soon aside of appearing in final smashes.
-Mega Man
0% - I don't think we will get any, not for a specific reason, I just feel like they'd rather put Capcom characters from a different franchise if anything.
-Wii Fit
0% - Miis are already in as their own thing and the balance board is not going to become a fighter
-Punch-Out!!
0% - The series seems too minor to get a newcomer... even with the Wii revival, it's still not one of the big Nintendo series, and no new games have been released after that one. I would call it a dead franchise like F-Zero and Earthbound.
-Mii(
)
0% - We're not getting a new Mii class. Mii costumes sure, but they don't count as newcomers.
-Pac-Man
0% - Despite Ms. Pacman would be a cool echo and the ghosts could be a creative concepts as a single character, we're almost certainly not getting any of that. We don't even have Pac-Maze anymore...
-Xenoblade Chronicles
0% - Sakurai made up excuses to not put the protagonists of the latest game in Smash, probably he (or Nintendo) doesn't want to. Three Houses has been released later and it still got a newcomer, while the Xenoblade one was too late.
-Duck Hunt
0% - See Ice Climber.
-Street Fighter
90% - Because if you think about it, he added an echo, not a full fighter... and it's even one of those echoes with more effort put in (the same thing that happend for Fire Emblem). Part of Incineroar's moveset is also inspired by a Street Fighter character, it means that Sakurai is a big fan of the series and won't lose the chance to put someone new from it in the game.
There are a couple of things against against this possibility: if spirits deconfirm... I don't know how many SF spirits there are in the game already and if there are major characters without one. The other way we're not getting a new Street Fighter character is if Sakurai makes no difference between SF and Fatal Fury, and the character I'm speculating is in his eyes Terry already.
-Final Fantasy VII
0% - or Final Fantasy in general. We got Dragon Quest already... unless he puts Sephiroth in, I doubt we'll get more FF stuff, if anything some other popular Square properties such as Tomb Raider or others.
-Bayonetta 2
0% - Like for Cloud, I think this is one of those series that will stay represented by only one character, the protagonist.
-Splatoon
0% - Inkling is already one of the biggest newcomer of Smash Ultimate, there's no need to add anyone else. Even if they added someone, there's not much choice... Dj Octavio maybe? But it's probably too niche. Octoling works better as an echo.
-Castlevania
0% - The franchise already got lots of content in the base game.
-P5 Persona 5
0% - I doubt they will put 2 DLCs from the same franchise at the same time... remember that Fighter Pass 1 is stil up.
-Dragon Quest XI
echoes of an elusive age definitive edition S
0% - Same as Persona.
-Banjo--Kazooie
0% - Same as Persona and DQ.
-Fatal Fury
0% - Same as Persona, DQ and Banjo.