Nah, not TWEWY characters. They wouldn't fit..
As much as I love the game (more than anyone's ever loved a game), I would be pretty disappointed to see them in SSB4. Not to mention it wasn't made by Nintendo. A reason I have a grudge against Snake and Sonic.
Imagine Gyarados on the final part of the FE stage or the Metroid stage with lava. He'd pass out from dehydration.
Beginning to work on my character moveset I promised, and proceeded to forget about, ages ago. It will be done in another age.