Perhaps write a few more;
Crash Bandicoot; "He's a Sony PlayStation character!" First of all "was", and second of all. Did you know that Crash had 5 exclusive titles on Nintendo consoles? And that he was only considered a mascot for the first PS? Also, he holds bigger ties to Nintendo than Master Chief for example, or anything Microsoft related with the exception of maybe Banjo & Kazooie. (Could have said Minecraft, but that's not history, that's current)
Heihachi Mishima; "He's from a fighting game, remember how Sakurai don't want that in Smash!" Well ... First of all there is subject a) Little Mac. "But he's a Nintendo all-star character!", does not matter, Sakurai and co made him work, which is nice! and Little Mac is no bigger of an Icon than Tekken's main guy himself. And subject b) Ryu from Street Fighter. Sakurai stated this before Ryu, but went ahead anyways. He tried to make Heihachi work, which means he care for the guy, and might just revisit the character, like Chrom.
Isaac; "NO ONE remembers Golden Sun or Isaac. Why do you think he was scrapped after Brawl?". OK, the series is dormant, we can agree on that, but that does not mean people have forgot about either Isaac or Golden Sun. Have you seen the cult following Isaac has had since Brawl? Isaac's fans has not forgotten him, and he does have a lot of moves to pull from to be unique. The series might have made him less of a priority, but with the Ballot, he has atleast shown up on the radar of Sakurai and co, 100% sure of.
Next one is a bit tricky, but I'll try. It's tricky because he is not that often talked about;
Doshin the Giant; "He is too big! I don't see any moveset potential. He is obscure as hell, why would Sakurai pick him? He's game only came out in Europe and Japan. Also he fits better as a stage/hazard/assist trophy!" Alright, that's a lot, but let's go over them, shall we?
1. Size is not an issue in Smash. Ridley and Olimar proves that. Also, he's whole gimmick in the game is about changing size, so it would only come natural for Doshin to change size if any.
2. Doshin is the incarnation of the bloody sun. He can turn into a demon. Check out my support thread for more inspiration.
3. Obscure? True, but is not that what Sakurai likes to give us? He'd be the perfect surprise. Also being exclusive to some regions has not been an issue in the past. (except for Takamaru, still, Marth, Roy in Melee and Lucas still)
4. True, Doshin is an interesting case, since he fits "Everything". I've heard good ideas of him being a stage, a hazard on a stage and him being an Assist Trophy, and honestly, I would not mind any, as long as there is anything Doshin related, I'd be satesfied, but I still want him as a playable character. He is a pipedream of mine.
That will be it for now.