I refuse to believe that that's actually been done.
So far, I can defeat 5 "Cruel Melee" opponents (Roy or Kirby) 4 opponents (Y. Link) or 3 opponents (Jigglypuff) in one game. My total is 27. 6 or 7 sounds impressive but possible... darn it! Now I have to play to find out! More Difficult bosses:
~ Bonetail (Paper Mario TTYD), yeah, yeah, I know I can level up...
~ Emporor Ing: Hard mode (Metroid Prime 2), kicks my ass with near-100% completion...
~ Cerberus Alpha: Perfectly (Mischief Makers), took many-a-tries, but I finally got him. Has anyone else ever played the bosses in Mischief makers for N64? The game is odd, but the bosses kick ass(in one manner or another)!
~ I know there's more but I can't think of them (to be fair, majority of what I've been reading are of games I haven't played )