Here's another fun set to try, but it's actually OU-worthy:
Mew @ Leftovers
252 HP/252 Spe/4 Def OR 252 HP/176 Def/80 SpDef
Timid / Synchronize
Snatch
Magic Coat
Protect / Softboiled / Psychic
Baton Pass
This is THE anti-baton-pass baton pass and anti-anti-stall pokemon. Sounds confusing, but it really isn't. Snatch steals any stat-up move, as well as nifty things like Substitute, Heal Bell, Roost/Recover/Softboiled/Rest/etc.. Magic Coat is greatly improved to bounce back Taunt, entry hazards, and phazing. Protect scouts for Trick and choice users' moves, allowing you to Baton Pass into an advantageous matchup. Max HP and Speed give this set the ability to pass out of most pokemon, though you could opt for a more defensive spread to better tank hits from threats assuming you mispredict. This isn't meant to defeat Dragon Dancers, though it can do that if you really want it to. It's meant to check bulky setup like SD Gliscor, Bulk Up and Calm Mind pokemon that stall struggles with. It can also stall out pokemon with Toxic Spikes quite admirably since Snatch can steal recovery and healing moves like Softboiled and Aromatherapy/Heal Bell, meaning a more defensive spread and Softboiled instead of Protect can be used as a defensive team's answer to opposing stall teams and common stallbreakers. The one stallbreaker that becomes a problem is NP Thundurus, but if you opt to run Psychic it can cleanly 2hko after Stealth Rock.