Alright, since ditto is becoming an interest again because of the possibility (only possibility no conformation of course) It might be wise to start discussing potential partners.
Some that come off the top of my head
Whimsicott: With priority stun spore, you can successfully allow an opponent to set up while knowing that you can slow them down to the point that ditto, even without a scarf, can come in, steal all the boosts, and out-speed. Whimsicott also serves as a safety net just in case ditto fails in preventing a set up sweep because of this. Additionally, Whimsicott can comfortably run taunt instead of encore because ditto's presence causes caution about set up anyway.
Gliscor: Gliscor's poison heal coupled with taunt aid's the team's ability to control what type of set up your opponent gets to use greatly. You want your opponent to have the urge to set up but not set up hazards, status, etc
Sturdy support users: Especially ones that are widely considered to be set up fodder for stat up users. You're going to want to make the temptation to set up on your team be as much as possible. However, you're going to want to have control over your opponent's willingness to set up hazards.The Magic Bounce users (mostly xatu) is a prime example of a good set up fodder that can provide you with screens, wish support, and prevention of hazard set up that ditto doesn't like.
If you were to use Whimsicott, Gliscor, and Xatu you would also want to use something...not weak to ice :P The best examples would probably be bulky waters such as slowking, vaporeon, etc.
Feel free to make other suggestions, my team seems to resemble stall and not offense but ditto theoretically can fit on any team as a revenge killer .-.