Hypothetical: Every week, the Smash Ultimate players in the US vote to ban a new character from online tournaments. Bans are permanent, so the character banned week 1 is never seen again.

Eventually, only one character remains - the least banworthy character online.

Who is it?

Frankly my money is on Robin, not because they're not banworthy, but because they're so forgettable that people won't realize they're even in the game until it's too late.