I have a nice moveset here.
Mew @ Leftovers
252 HP/252 Spe/4 Def
Jolly / Synchronize
Snatch
Magic Coat
Protect / stat-up / Tailwind
Baton Pass / U-turn
This set's total magic. Snatch stops bulky setup, while Magic Coat bounces back status and hazards. Protect scouts for choice users' moves (and moves in general), and U-turn lets you switch advantageously. Baton Pass trades the ability to do damage on the switch to pass boosts along to somebody else on your team. Protect and Baton pass go well together, while Tailwind and U-turn let you support your team better. You can also run a stat-up move on Mew, but then it's just a regular BP set with snatch over softboiled. Leading with this is best, since it's designed to get the jump on most leads.
Mew @ Leftovers
252 HP/252 Spe/4 Def
Jolly / Synchronize
Snatch
Magic Coat
Protect / stat-up / Tailwind
Baton Pass / U-turn
This set's total magic. Snatch stops bulky setup, while Magic Coat bounces back status and hazards. Protect scouts for choice users' moves (and moves in general), and U-turn lets you switch advantageously. Baton Pass trades the ability to do damage on the switch to pass boosts along to somebody else on your team. Protect and Baton pass go well together, while Tailwind and U-turn let you support your team better. You can also run a stat-up move on Mew, but then it's just a regular BP set with snatch over softboiled. Leading with this is best, since it's designed to get the jump on most leads.