Not going to even touch on this because I believe Golden summarized my views on this pretty nicely, also apology accepted (even though he actually can do those things).
Well it is my personal belief that this should be a very important thing to think about when discussing third-parties, but yeah you gave me the benefit of the doubt here so I'll stop while I'm ahead.
Despite the fact that Black Shadow has been shown to this in his own canon, I'll humor you here.
That wouldn't change the fact that Sakurai has made movesets for Fox, Captain Falcon, Ice Climbers, Zelda, Sheik, Falco, Mr. Game & Watch, Pokémon Trainer (Especially Ivysaur), Olimar, R.O.B., Wolf, Villager, Wii Fit Trainer, and Rosalina. They've been given fully-fledged movesets (most of these unique) with fairly little to go by when it comes to the thought of them in a fighting game.
So even if the presented abilities were "made up", I imagine it would be safe to assume that Sakurai could easily come up with something Black Shadow if he really wanted to. Same easily goes to Little Mac as well.