FM-Tobi (or Orochimaru) - front line
Sannin Oro (or Tobi) - Shurado - back line
Summon: Fukarukamaru
Use the repulse chase and the genjutsu mirror, plus the fire dagon mystery.
If you don't have Fuka, try your other summons and see which works best and completes your combo.
With this team you will do a 8 combo at the start of the first round with your clone's normal attack (or Orochimaru's guaranteed repulse), and if by some miracle the opponent's character survives the initial combo (depends on the battle power, of course), you can finish him in the next round guaranteed. The dmg you would do is immense not only because Tobi and Shurado are hard hitters, but also because of the Genjutsu mirror which will increase your dmg to ignited target by vast amounts. So you can change your chase depending on your summons and such, but the Genjutsu mirror is the key to all of this.
The team is a little squishy, but Orochimaru's revive, your main's clone, combined with Tobi's mystery dodge, you shouldn't have any problems.
The only people you can lose from are those with overwhelming battle power (but in that case it wouldn't matter which team you'd use anyway)