Well, assuming he has the ability to carry other characters, I'd say pretty much anybody that has a poor recovery, preferably one that doesn't hit above them and/or sends them back down like aether. otherwise, I think Tails would have a strong air game overall, so any character with a good ground game would work to compliment that.
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So we got another theory to maybe help back us up. someone in the Geno thread recently shared
this reddit post regarding the potential remaining newcomers by using the patterns of the Blog posts. and while I'd be considered a "box theorist," I have to say I'd rather believe the math here.
In short, the average number of character trailers shown for the smash blog posts per week equals 2.9, meaning if that remains consistent for the remaining 12 weeks we have until release, there would be approximately 8 characters unaccounted for.
This also doesn't affect most other theories being talked about right now, such as the music theory, or the Mii costume theory. The only one it does seem to conflict with is the Box theory, which at this point, I'm willing to agree that it is not final.
here's hoping that the math doesn't fail us here, and that Tails is one of these supposed 8 characters!
The problem with this is the blog hasn't really been consistent. Most weeks yea there have been at least 3 characters a week but there have also been weeks where there were 4 or even just 2 characters.
There are 57 blog days left. With 28 known characters to go (And likely at least 2 more to be revealed), 7 new items, 5 new pokemon, and 8 assist trophies. There's also posts for stages even if they're old though they tend to only go up on music days since they usually add something more after the music is up. When it's not a stage it's usually an item of some sort. But anyway, that's 50 of the 57 but you also gotta account for music.
Tonight's update is probably Animal Crossing music after Isabelle's reveal. In fact there are 12 music days left (11 after today) before release. Assuming they don't just have another day where they have an unrepresented franchise get music. As Jigglymaster has been keeping track: Punch-Out, Pokemon, Earthbound/MOTHER, Kid Icarus, WarioWare, Wii Fit, Duck Hunt, Sonic, Pac-Man, Star Fox, Xenoblade, and possibly Mario Kart (Since for some reason there's 2 Mario sections in the music). Meaning it's quite plausible each of the remaining music days will be a different franchise though one would have to be left out (Probably either Duck Hunt since I'm not sure they'll really have much to remix with what they already had in Smash 4 or they may not do a Mario kart track since in regards doing the different variety of franchise music, Mario Kart may still count with Mario when we already got that fortress boss remix) at least until after release
Subtracting music days from the 57 there's 45 blog posts for other stuff meaning the characters plus new content for potential blog updates are more then blog days before release. Albeit certainly some of the the music posts may be accompanied with an item, assist trophy, or one of the new pokemon rather then a stage. Stages are pretty much the filler updates though since obviously there's no way all the stages will have a blog post on the site before the release date. Even if every music day from henceforth comes with Pokemon or assists there will be a few that won't be on the blog until release (Though it would knock out most of them and the others could be on other days randomly. But still most have accompanied stages). So not everything may be up by the time the game releases though if they do keep the 3 character's a week pace then yeah they may have all the characters up on the blog about 1-2 weeks before release. But be wary of the possibility they may only put up 2 sometimes or even just one or zero if they run out quickly enough.
History of posts accompanied with music days from most recent to the first music day
Pikmin music with Summit
Mario music with Final Destination
Yoshi music with New Donk City
Fire Emblem music with Togedemaru pokemon
Donkey Kong music with Dracula's Castle
Castlevania music with... Castlevania characters (This is kind of a special case where music day happened to fall on the day of a Smash Direct)
Galaga Medley with Lylat Cruise + Fake Smash Ball
F-Zero Music with Melee Peach's Castle
Metal Gear music with Wily Castle
Mega Man music with Alolan Raichu
Kirby music with Kongo Falls
Noisy Notebook with Sukapon assist trophy
Splatoon Music with Bomberman assist trophy
For the most part yeah, Music comes with mostly stages. But assist trophies and Pokemon are also kind of common with music.
Another thing looking back though there are days where they put up 3 things in one day so again that's an inconsistency that might be overlooked in trying to analyze the blog to determine how much is left character-wise.
