I know it's probably been suggested before, but this would just be awesome. Much better than Special Brawl, anyway, and probably much more popular, and may even be played online. At the beginning of the match, one person is randomly selected as the "King of the Mountain." When that person dies, the person who killed them (or at least got credit for their K.O.) becomes the new King of the Mountain. This pattern continues until the match ends, and whoever is the King at the end of the match (personally I think this works better with Time than Stock) is the winner. The King could be visible by a crown icon on their character icon and maybe even some sort of gold halo or something above their character itself. Obviously this mode would only be viable with the full four players - 1v1 in this mode would just be a wild goose chase/massive camp-fest.
Thoughts? --- darkx remembers his friend, GrapefruitKing. RIP :( My SSB4 roster prediction: http://i.imgur.com/Me1I6s5.png