Two sets I thought of (one is posted already in some form I'm sure)
Zoroark @ Life Orb
Modest 4 HP / 252 Sp Atk / 252 Speed
Ability: Illusion
-Dark Pulse
-Agility
-Flamethrower
-Focus Blast / Grass Knot
I'm betting most pokemon will expect Zoroark to NP, if they even predict him in the first place! With an agility Zoroark out speeds everything not named Ninjask or Deoxy, even if they have a scarf. Modest + Life Orb gives this set great power. FB and GK are for coverage, I'm a bit iffy about using FB due to accuracy but it hits every thing resisting DP and FT. Grass Knot is an alternative but only if you have Swampert trouble (Or if you rage about FB's 70% hit rate) Illusion isn't even necessary for the set to be useful, which is what I decided on while making this set. Though it will occasionally allow Zoroark a free turn of set up or even a free hit. Good Teammates include Ghosts, a good Ttar/Heatran counter, something to kill Blissey, and perhaps Dual screens and an alternate agility user (doesn't need agility just the capacity to use it) Priority is also a threat to deal with. An alternate move is memento, since you outspeed everything you can use it when you are near death to help another sweeper set up and finish things off.
LEAD
Timid / Jolly 252 (Sp) atk / 252 speed
Focus Sash
Dark Pulse / Trickery / Night Slash
Counter
Sucker Punch
Memento / U-turn
This lead is all about messing with the opponent, Dark Pulse or Trickery to hurt suicide leads, then finish them with sucker punch, hopefully they used the turn setting up SR and you'll get off without breaking your sash, allowing you the ability to counter, memento, or straight up attack the switch in. u-turn can be used if you either have a rapid spinner, also if you send in Zoro under the guise of a spinner you can massacre the ghost they send in. If you use DP then max out Sp atk other wise max out attack to get more damage off of Sucker Punch.
Feel free to add suggestions, especially to the lead because I think it has potential to defeat a lot of common leads if you choose the correct attacks.