EVs: 252 Attack, 252 Speed, 6 Def
1 Swords-dance gives you Great attack and it is easy to set up most of the time thanks to Bellossom's Bulk. Drain-punch is for coverage and recovery. Leaf-blade is for STAB. Nature-power becomes Earthquake in PO/Wi-fi, Sunny-day would be there if you don't have Sun-support.
RE-EDIT: With new information released about B/W2 there is a move tutor for Drain-punch so this set is possible!!!!!