So here is an interesting question of the Smash Bros after the upcoming one. - For sake of argument I'm using the newly announced IP.

What do you think would qualify it to have characters for Smash Bros? A massive cult fandom? Huge sales? Massive review scores? - For measurement of 'cult' lets say that we're talking about people with atleast 500+ hours in it and/or bedrooms dedicated to it.

Whether Sakurai thinks he can make something interesting with the character. From what we've seen, I think an Assist Trophy would be great...

Whether Sakurai feels it's right to include it.

Sales.

Sales as in to maybe make future installments, but Sakurai would add anything on a whim or if there are lots of fans.

I think it literally comes down to whether Sakurai or not thinks it'll work/be a fun troll.

I can see it working in Smash, but I guess it also comes down to the SP in Splatoon and how fleshed out the characters/world are. Fingers crossed its as fun as a whole as the MP looks.