Okay boys and gals strap your tinfoil hats on and entertain this theory:
Spirits Mode: you start with original 8 Smashers , all the other characters have had their souls ripped out of them and their bodies have been turned into ***drumroll*** special assist trophies. Once you fight the boss character relevant to the character you unlock the character assist trophy helps you take on the boss.. once you defeat the boss, the assist trophy is imbued with it's spirit again, character is unlocked, Grinch leak supposedly shows assist trophies , but then these specific ones become real. Leakers are correct , Grinch is correct, incineroar gets struck by lightning , DLC gets purchased in the future and must be unlocked the same way in spirits mode. Spirits mode has 2 S's in it. Assist Trophy has 3 S's in it, 3 comes after 2...
.... Illuminati Confirmed?
Or we get Ken, Incineroar, Chibi Robo, and a frickin L shaped Tetromino and there's an unlockable Easter egg in the game of the Grinch being violently murdered by Sakurai