-= Geno =-
Geno has a lot going for him: Mii Costume is still MIA, two potential leaks pertaining to Mii Costumes, specifically SquareEnix costumes, don't mention his Mii Costume returning, three of the biggest longtime fan requests are already in the game and most of the other newcomers have been chosen based on fan feedback, Super Mario RPG is yet to see rerelease via NSO which may indicate some sort of tie-in, Sakurai himself agrees that the character would work well in Smash, the list goes on and on. Honestly, It's amazing how much he has going in his favor.
I personally don't have a very strong connection to the character, never played his game (I plan to do so when it comes to NSO), mostly heard of him during the Brawl days via Newgrounds flash animations (funnily enough, I don't actually like Rawest Forest. In fact I find it kind of annoying. actually). But I'm right there with everyone else when I say I'd love to see him make it to Smash.
-= Crash Bandicoot =-
I don't think it would be an exaggeration to say that when Banjo & Kazooie came to Smash, it was truly the end of an era. One of the biggest NEVER EVERS finally getting into Smash despite many people's (myself included) doubts. It was an amazing time, so much joy to be had, hype was at an all time high. But this hype got me wondering: How could they top this? What other characters could they reveal at this point that would get people as excited as Banjo & Kazooie? I could only think of two characters that I thought could match it, and one of those was Crash.
Crash getting into Smash would be amazing. To have yet another one of Gaming's most iconic 90's platformer mainstays join this game would be beyond incredible, and I'd love to see what kind of wacky moveset they could pull off with him. I think there's a good chance he'll actually happen this DLC Pass, and having alleged insider information like this certainly helps:
https://twitter.com/MandyCanNot/status/1186504943877967872
https://twitter.com/MandyCanNot/status/1203407675150745601
https://twitter.com/MandyCanNot/status/1216800286452396033
https://twitter.com/MandyCanNot/status/1219170163838390273
Here's hoping he's right.
-= Ryu Hayabusa =-
When I had first heard Ryu's name pop up in speculation, I honestly didn't care all that much. But unlike other names such as KOS-MOS or Reimu, I actually really started to warm up to the idea of Ryu joining Smash. I think it helps that I has just recently beaten the original Ninja Gaiden in one sitting without savestates via NSO, but either way I'm totally in favor of him joining Smash. He for sure feels like one of the last big NES characters to have yet to make it into Smash, and I would love to see him get in. Bonus points for having an NES alt.
-= Doomguy =-
Crash was one of the last characters I thought would be as hype as Banjo, and Doomguy is the other one. I think it's absolutely terrible that one of the quintessential video games, the grandfather of most FPS games, and one of the most metal game franchises out there, has yet to make it to Smash in some way. Doomguy would bring a very unique playstyle to Smash, using mostly guns to attack his opponents alongside the occasional chainsaw. I don't even think his signature ripping and tearing would be enough to prevent him from getting in either, since Smash doesn't really have much in the say of blood and gore to begin with.
One thing that's certainly helping him stay on people's minds is the CacoMallow Post, which if true seems to indicate we'll be getting DOOM content sometime in the future. A lot of people believe that this post could mean Doomguy would be coming as a costume rather than a fighter, but I really don't see that happening because A) It would be weird for them to include someone like Dragonborn or the Fallout Boy and include more DOOM costumes than anything from those series, and B) If they were to include Doomguy as a costume, why even bother with the Cacodemon Hat? Surely Doomguy's Praetor Armor would be enough.
-= Lloyd Irving =-
Much like Geno, Lloyd and Heihachi are two major third party characters that had costumes in Smash 4 that have yet to return. I think it's safe to say that a Namco character is coming to the game at some point, and it's likely going to be one of these two. While Heihachi is the bigger name, and was considered for Smash 4 as a DLC fighter at one point, he was rejected because they couldn't find a way to incorporate the Tekken gameplay style into his moveset, so I'm putting my money on Lloyd getting in.
Tales Of may not be on the same level as Final Fantasy or Spongebob in terms of popularity, but it's a pretty big deal. The fighting style of the Tales Of series seems tailor made for a Smash moveset, with combat being done on a sort of 2d plane and special moves being set to different directional imputs like Special Moves in Smash are. It's also worth noting that Tales Of is recently celebrating it's 25th anniversary, so what better way to celebrate than by getting a character in Smash?
-= Sora =-
Gonna be honest, I don't particularly care for Sora one way or the other. Never played the Kingdom Hearts games (and given how much of a cluster**** the story is, why would I?) and I have no attachment to Sora personally. That said, I know that people really want to see him get in Smash at some point, and I'm all for seeing people get what they want, so I'm not opposed to him getting in. That said, I'd very much prefer Geno gets in before he does. Not that I think he's competition for Geno anyways since, being wholly owned by Disney and not Square, he's not. It's just what I'd prefer to see happen.
Anyways, that's my reasonings for all of them. Sorry if this is a little rambley and unfocused.