How about a game until a new major leak pops up? (I have an odd hunch we'll know everything about the game by late September and a September or October direct will confirm some big controversial leak)
You can add up to 4 new characters, literally anyone you want that has appeared in a video game before (yes, even shrek or Goku, but preferably from a Nintendo console game or handheld), but you have to axe a character from each previous SSB game.
To get your first character, you must remove someone from Smash for Wii U/3DS. That character will also no longer appear in Ultimate so choose carefully!! To get your second character, you now also have to remove a character from Brawl (and they wouldn't appear in any future games, including Ultimate!). To get your third character, go back to Melee, and if you want that final character you need to axe an original 12.
You can choose to add up to 4, but don't need to add 4. I'll go now as an example:
Character 1: Banjo-Kazooie
Character to Cut for Banjo-Kazooie (reminder, first character cut is from Wii U/3DS and is also removed from Ultimate): Dark Pit
Character 2: Doom-Guy
Character to be cut for Doom-Guy: Toon Link
Character 3: Sylux
Character to be cut for Sylux: Pichu
Character 4: N/A
Character to be cut for N/A: Not Applicable (Never want to cut an original 12 personally)
I want to see who you guys would want to add and who you would remove to get them.