Problem is I'm pretty much down for any character that joins Smash because that is just another opponent that could be interesting to fight.
King K. Rool - I pretty much have no attachment to this character. He seems like a cartoony goofy villain in the 3d appearances i've seen, and I only saw one of his boss fights in one of the games (gamegrumps were playing it). The main reason why I don't care is I view King K. Rool the same way I view bowser and they do have a lot of similarities. Fun character to fight every once in a while, and not a character that I wouldn't complain about playing if I got them when picking random. Basically not a bad character, it's just a character that's not amazing.
Krystal - It's been so many years since I've played a Star Fox game, and the only one I own is Star Fox Assault (which I loved btw...). So while I may have wanted Krystal in before, I just don't care so much anymore just because I don't play Star Fox a bunch. Though I bet a lot of people would like her in.
Black Shadow - 2 reasons. More reps for F-zero, and it will give an excuse for Ganondorf to stop being a clone of Captain Falcon. I haven't played a F-zero game so it's hard to care about someone I know nothing about.
Xenoblade 2 rep - I don't know anything about Xenoblade 2 (I watched chugga's whole playthrough of Xenoblade Chronicles, and I played Xenoblade Chronicles X until I hit a hard wall of grind since I don't have the time to grind anymore). Though I've heard many people praise Xenoblade 2 sooo much so it'd be nice to see people happy for that. (Though.... if there's more wooshy wooshy laser swords like with Shulk, I might be interested)
Then a bunch of third party characters