I don’t think Banjo-Kazooie or Conker will be the character. They would have to be really small and while that is possible (take a look at Toro/Kuro in SFxTK), I don’t really know if that’s something Iron Galaxy would want to tackle. I personally feel like it would be harder than getting Aganos in the game. Since they are so small, mid and high attacks wouldn’t look like they connected (it would look like a punch going over their head or something, as an example). Of course, they could always make the characters larger or something – but that just wouldn’t look right in my opinion. Also, they seem to really like diversity in their Seasons, and we already have one goofy/weird guest character (Rash) – so I’m pretty sure the second character will be someone more “serious”.
I also highly doubt it will be a Mortal Kombat character. Some people think Scorpion will be in for some reason, but why? Scorpion is owned by Warner Bros. and they currently have a partnership with Sony. It would make no sense at all for a MK character to get in. Some people also think one of the guests will be a horror character like Micheal Myers. I don’t think that would happen because that’s kinda MK’s thing, and I doubt Iron Galaxy would want to copy them and do the same thing. Also, if we are talking about Micheal Myers specifically – there’s no way he will get in, because he’s also owned by Warner Bros.
Characters like Lara Croft from Tomb Raider might be a slight possibility, but I still doubt it. Square Enix has only made a deal with Microsoft for Rise of The Tomb Raider to be a TIMED exclusive, so the game isn’t even a 100% exclusive Xbox game. I don’t see Square Enix in making another deal with Microsoft to put her in a fighting game. I just don’t.
Cortana has an okay-ish chance. She IS apart of Windows 10, which is the platform that Killer Instinct is coming to (of course). I could see them trying to market that a little bit. She’s a Halo character, but she is also apart of Windows 10. Kinda fits actually… aside from one thing. What would her moveset be? And how would she be fighting? I just don’t see how they could make it work, but I’m sure they could come up with something if they really wanted her in.
Arbiter has a good chance. Halo 5 did come out recently, so I can see them wanting to do a character from that if they didn’t want to do another Rare character. And from what I’ve seen from his design (I’ve never played Halo, so I can only look at stuff on the internet) he seems to kinda fit. Wouldn’t surprise me if he made it in.
Joanna Dark has the biggest chance in my opinion, especially since Adam said that the gender would giveaway the character. If you say “the character is a male” there’s tons of things that come to mind as a possibly, like Master Chief, Marcus Fenix, Arbiter, etc. If you say “the character is a female” really only one character comes to mind – Joanna Dark (and maybe Cortana). So if he thinks the gender would give it away, I personally feel like the gender would have to be female – in which case, it’s probably Joanna Dark. Get what I mean? If it is true that he said the second character would be more of a surprise, keep in-mind that he could just be trying to mess around with us and throw us off. Maybe he’s trying to get people to expect her a little less to make it more of a “surprise”?