Honestly I thought this was kind of a given. I mean Sonic is in it, and the blue hedghog has a pantheon of supporting characters just as iconic as Mario's sycophants. So it makes sense to add some characters from Mobius and who better Sonic's sidekick Tails. I mean I would've been fine with Knuckles too, but Tails is clearly the second best choice from the Sonic universe.
Preposed Moveset
Up B: Tail Spin (He spins his tails, he flies up, he hurts people)
B: Some Sort of Mechanical Gun-Thingy (some sort of mechanical gun-thingy)
Over B: Spin Dash (like Sonic's, but slower)
Down B: Spin Charge (like Sonic's, but slower)
Final Smash: Either Super Tails (he's invulnerable and has Super Flickies that attack people) or he gets to use his Tornado walker.
B: Egg (Kazooie shoots an egg, maybe like 75% chance of regular, 10% for ice or fire, 5% for grenade)
Over B: Beak Barge (Kazooie's beak rams somebody, slow and powerful)
Preposed Moveset
B: Plasma Gun (he shoots his plasma gun)
Over B: Weopan Copy (Mega Man copies an opponets Over B move)
Down B: Mega Ball (a ball that rebounds around until it hits someone, the longer it's out the weaker the attack when it hits)
Final Smash: Hyper Mega Man Adapter (he grows taller, gets wings and jet pack, and has rockets all over him)
All his old moves.
Final Smash: Roy rapidly moves on the platform he's one and strikes a deadly blow to whoever may be foolish enough to be there.
The Viewtiful Joe series have been great innovative games, and Joe has already done a Super Smash rip-off so he's no stranger to this sort of set up. Though he's no longer wowing the video game realm, I'm thinking his moveset would be a very cool addition. I wonder if his VFX meter should be accoutned for though in someway, like he'll turn into regular Joe if he uses too many special moves.
Up B: Corkscrew Jump (You know, a corkscrew jump)
B: Zoom In (Paralyzies foes within a certain proximety)
Over B: Slow (Joe does powerful, super slow punch [maybe kick], but will automatically dodge any attack that is attempted on him)
Down B: Corkscrew Slam (like the jump, but impact on the ground sends shockwaves)
Final Smash: Mach Speed (Joe goes super fast and punches every thing on the screen ending on fire)
Pokemon Trainer was a cool idea, so why not do it again with another set of pokemon? Kind of like in the story where you have a rival this is like that. Now we could just do another set of starter pokemon from another generation, but that would be a little like the regular Pokemon Trainer, besides I'm partial to the original 150, so here is just some iconic pokemon you're used to from the original. We already got Water, Fire, Grass, Electric, Psychic (I think), and whatever the fuck Jigglypuff is, so let's get some new types.
Geodude
Up B: Tackle (Geodude shoots up and shoulder slams you)
B: Earthquake (Short range earth shaker)
Over B: Rock Throw (you throw a rock)
Down B: Switch
B: Hyper Beam (Charge shot that can't be saved, will be released when at full power)
Over B: Agility (Lunges out quickly)
Down B: Switch
Gengar
Up B: Dream Eater (Gengar launches upward and passes through people doing damage)
B: Lick (Gengar licks you, and you are stunned a bit)
Over B: Nightshade (A very wide beam is shot out, but doesn't go far)
Down B: Switch
Preposed Moveset
Up B: Extra Fly (He flies more and it hurts you some how)
B: Plasma Breath (Ridley's plasma breath)
Over B: Fireballs (Ridely's great balls of fire)
Down B: Tail Swipe (that'll fuck you up)
Final Smash: He could turn into Omerga or Meta Ridley or just grow humongous and wreaks havoc.
Peposed Moveset
Up B: Mega Slam (thrid jump that at it's height, Rash slams his fists downward)
B: Giant Fist (large powerful fist[ing hehehe])
Over B: Ram Headbut (the ram horned headbut from the game)
Down B: Boot Punt (the huge ass boot from the game)
Final Smash: It's be cool if those impossible to avoid race things would move across the screen and eveyone but you had to dodge it.
Fuck Bowser Jr., okay? Honestly I've got nothing really against him, only that since he appeared, we've heard nothing about Bowser's seven other kids, the originals (though breaking news is informing me they were in Mario & Luigi Superstar Saga, but I don't count that, because I'm writing this paragraph). I'm talking Larry, Morton Jr., Wendy O', Iggy, the weird one on the ball, Roy, and Ludwig Von. What happened? Were they all shipped off to boarding school or something? Really I don't know how this would work, maybe they all have the same moveset and speed and changing the "color" changes it to a different one, or maybe you only have one, or you can switch out like Pokemon trainer, what do I care? Let's just represent some other Koopa Kid love for once.
Up B: Koopa Whirl (they go in shell and spin upward, much more so than Bowser's but harder to aim)
B: Wand Beam (they use their wand thingy from Super Mario Bros. 3)
Over B: Special Unique Move (that each particular kid has; look I just don't want to think anymore ok?)
Down B: Koopa Slam (they slam down butt first, like you do)
Final Smash: All seven appear with a weopan (a chainsaw, katana, brass knuckles, chains, dual weilding Uzis, battle axe, and sawed-off shotgun) and just start killing and decapitating eveyone, until those smug Mario Brothers, who think it's cool to beat up children, have their heads on pikes and are surrounded by a flowing river of blow that curses all who touch it.