In my opinion the set should be Synthesis, Rapid Spin, Toxic, Energy Ball, it probably need Spin to at least have niche and Toxic helps against a lot of things it couldn't do anything otherwise (such as P2), can't touch Steel/Poison types (and can't do even Poison the spinblockers Doublade and Haunter, but at least there are 2 Pokémon who can Spin so if you don't want to get rid of your own hazards can be an option.I want to bump this because Middle Cup is one of my favorite metagames, and I'd hate for it to die from inactivity. So let's bring attention to one of the new Middle Cup Pokemon "Steenee", part of the Tsareena evolution line. I'm gonna be honest, it's pretty terrible in terms of its base stats. But if you feel like being creative and giving yourself a challenge, it's worth a try.
Steenee @ Leftovers
EVs: 252 HP / 252 Def / 4 SpD
Impish / Bold Nature (Depending on whether you're using Physical or Special attacks)
- Play Rough / Dazzling Gleam
- Teeter Dance / Toxic
- Payback / Energy Ball / Leaf Storm / Low Sweep
This was basically the most useful set I could come up with for Steenee. The unfortunately problem is that it has mixed base attacking stats of 40, so it's not gonna be doing damage at all for the most part. It gets access to Synthesis / Teeter Dance which at least gives it a little bit of viability, along with some odd standout moves such as Payback, Acupressure, Aromatherapy, Low Sweep, Light Screen and Reflect. So there's possible other options in there.