Nintendo's go-to strategy for when they need characters to fill a lesser series has always been "use the Mario cast", but what they should be doing is what they do to make their best franchise: use everyone's cast. Think about it. Instead of Mario Golf, we'd have Super Smash Bros. Golf. Instead of Mario Kart, we'd have Super Smash Bros. Kart. Instead of Mario Party, we'd have Super Smash Bros. Party.