Sableye (Leftovers, Impish) (252 Defense, 252 HP) (Prankster)
-Will o wisp
Standard Sableye. It burns stuff and can heal off damage with Recover. Night Shade is to do some damage maybe, and Taught is there for defensive/setup/etc Pokemon.
Sharpedo (Adamant, Life Orb) (252 Attack, 252 Speed) (Speed Boost)
A physical Sharpedo used for revenge killing.
Gyarados (Adamant, Cell Battery) (252 Attack, 252 Speed) (Moxie)
A setup Gyarados. It takes advantage of electric attacks with Cell Battery, and can obviously wreck havoc.
Venomoth (Modest, Leftovers) (Unsure on EVs) (Tilted Lens)
A Baton Passing Venmoth. Not much to it.
Porygon-Z (Modest, Life Orb) (164 HP, 252 SP. Attack, 92 Speed) (Download)
An Agility Porygon-Z. It can also take advantage of Venomoths Baton Passed Quiver Dance.
For the last slot, I'm thinking Hydreigon or Magnezone.