As mentioned in the previous post, Nintendo is actually legitimately taking suggestions for Smash Bros. DLC characters! (I know, I can barely believe it either.) Every entry will be seriously considered by the team, so your suggestion for Krystal needs to be serious as well. As a sample, here is what I submitted (or tried to submit, the site appears to be taking a pounding right now). It's short and to the point due to the 500 character limitation.
One thing I want to stress above all others is this: when making your suggestions, please be positive! Talk about the advantages Krystal has in and of herself, as well as how she is differentiated from other characters. Speaking negatively against other choices as a way of making Krystal sound better is not a very friendly tactic and probably won't win you any respect from the developers. After all, the other fandoms want to see their characters too. We should be happy and supportive of their efforts as well. We're all gamers! We should be friendly to each other as we are (virtually) smashing our opponents off of stages and into bottomless pits.