When I mentioned adding Kumatora into Smash Bros, I argued that Kumatora would make an interesting new character with an all new move set separate from Ness or Lucas.
Today I propose the opposite. Add another clone character similar to Ness or Lucas, and that character should be Paula from SNES niche classic Earthbound.
Due to her use of physical and magic attacks in Earthbound, she would fit the well rounded structure of Ness and Lucas. I also believe every Earthbound player would agree that 'Pray' would make one amazing final smash.
Due to the clone nature, perhaps Paula could even replace Ness or Lucas, though I find that to be an incredibly long shot. Though it could be argued that the real hero of Earthbound is Paula, but that is a separate discussion.
In the end I hold onto a more realistic hope that she at least makes an appearance as an assist trophy just as Jeff did in Super Smash Bros Brawl on the Wii. Of course, I can always pray that there is more in store for her in the game.