This section is actually still alive? lol
Jokes aside, what would the WiiFit trainer's rage be? or other abilities?
I'd probably look at the WiiFit trainers as fitness gods.
They can super jump.
They can spike with their feet like in Smash 4 (implying really good super gravity).
I would show them to be a bit more light, but quicker than most hales.
His/her rage could be a short stun radius with the ability to hurl one fireball of great magnitude (probably using Reload) at the opposing team. Uncertain of whether it should be reflectable or not; in smash this would be her Sun Salutation B special.
You could probably rip some of their taunt lines from Smash 4, as well as other vocal pieces for an intro, outro, backstab, rage, etc.. and for music, you could either find wii fit music or use Nonon Jakuzure's theme from Kill la Kill. <3
Whether or not you take all of this into mind or not is solely up to you; it would be awesome to see the Wii Fit trainers x3