Joker (Persona/SMT): Whilst the chaotic part of me wants to say either Elizabeth or Aigis, my vote has to go for the Jack Bros. - that is, Jack Frost and Pyro Jack working together. Acting as a very interesting nod to the Virtual Boy title, as well as being some of the most popular demons in the series, they'd be cool additions with plenty of personality - hee-ho!
Hero (Dragon Quest): Slime. Feels like a logical choice to me, plus a cool idea for a composite character of sorts. Admittedly, I know very little about Dragon Quest... sorry.
Banjo and Kazooie (Banjo-Kazooie): I guess Mumbo Jumbo? I don't know Banjo-Kazooie well, but the idea of him being able to turn into different animals for his attacks sounds like a lot of fun.
Terry (Fatal Fury/King of Fighters): My own pick here would be Iori Yagami, but with the added benefit of his Go!! meter allowing him to change form into Orochi Iori - giving him a boost in speed and attack power, though only for a limited time and with a significant debuff in defence.
Byleth (Fire Emblem): Hmm... I'm actually going to say Kiran, from Fire Emblem Heroes. Aside from being a mobile rep, his summoner archetype would really make him unique in the cast - plus, he'd surely be original enough not to get dislike-bombed on YouTube.
Min-Min (ARMS): Personally, I'd love to see Helix. His zany personality, combined with his really unique liquidy animations, would make him a really fun inclusion to see, and might differentate him somewhat from Min-Min.
Steve (Minecraft): Hmm... there's not many characters from Minecraft that would work well as fighters, but a unique archetype to see could be a Villager. The idea would be, they have a similar mechanic to Steve but moreso representing trading, as well as the potential to have different attacks based on their various roles, and skins based on either different colour palettes, or different models like in the more recent updates.
Sephiroth (Final Fantasy): I'm a little torn on this one. The idea of a character like Tifa getting in would, admittedly, be cool - and a gunslinger archetype in the form of Vincent would be a nice twist on the Smash formula - but my vote goes to Black Mage, simply because he could bring the Final Fantasy magic system to the table. Would he have similarities to Hero? Potentially, but I don't think Command Selection would fit him. Rather, his various magical attacks are more organically fitted into his moveset (a little like in SSF2.)
Aegis (Xenoblade): I suppose Elma, from Xenoblade Chronicles X? I don't know much about the Xenoblade series, admittedly, and I suppose she'd make a lot of people happy - as well as bringing X music to Smash, which would be nice.
Kazuya (Tekken): Given my incredible lack of knowledge on Tekken, I'm going to just toss out King - being a cool design with his leopard mask, as well as a fighting game grappler, he's a cool addition I suppose, plus he'd fit in pretty well.
Sora (Kingdom Hearts): King Mickey Mouse. I know by far the least about Kingdom Hearts, but the idea of an exceptionally edgy rendition of Mickey ****ing Mouse being playable in Smash Bros. is so funny to me, I'd probably be fine with it.
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