Who has a shot- Obviously any character Nintendo owns has a chance. I'm pretty sure most developers would kill to have their characters in Smash, but only ones that have a close relationship with Nintendo have a real chance. Mostly old Japanese companies unless the big N is making an effort to reach out.
You probably need to be popular on both sides of the Pacific to make it too. A vocal fanbase doesn't hurt and you don't want to be too similar to a character already in Smash.
Waluigi - I just don't see what would make him different from Luigi. Waluigi still needs to develop as his own character before I'd want him in Smash.
I just remembered another idea I had- Proffesor E. Gadd. He's the fellow who designed the Polturgust in the Luigi's Mansion series and FLUDD from Mario Sunshine. He's shown up in a few other Mario titles as well.
CotW is a method for ranking cards in increasing order of printability.
*"To YMTC it up" means to design cards that have value mostly from a design perspective. i.e. you would put them in a case under glass in your living room and visitors could remark upon the wonderful design principles, with nobody ever worring if the cards are annoying/pointless/confusing in actual play
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