Yeah, since I love rooting for the underdog, that's yet another reason why I love Mother 1 and Ninten. And from a lot of the requested characters for Smash, I think he's a good candidate for the "underdog" title. As he would be the underdog when it comes to Smash and even the series he comes from, since his game is kinda overshadowed by the other two games.
This is also another reason why I think we need a Mother 1 remake. That way Smash fans, Mother fans and the general Nintendo audience can actually see Ninten as his own character. Not to mention introduce the Mother / Earthbound series to the public.
Speaking of a Mother 1 / Earthbound Beginnings remake, since Giegue says that Ninten will meet him again, wouldn't it be cool if you actually have a secret boss or extra content where not only do you get to see more stuff, fight more enemies and see more locations, but also fight Giegue? Maybe even on a 1v1 after separating him from Ana, Lloyd and Teddy?
I think that's a great idea of expanding the lore of an RPG from the 80's, along with it being a good and possible idea for extra content.