Posted too late, JCM took my first Idea! XD
Roselia@Life Orb
252 Speed 252 SpA 4 Hp
Timid Nature
Natural Cure
Venoshock
Leaf Storm
Cotton Spore
Toxic
This set is designed to beat all offensive threats that decide to switch in on roselia, and then kill them with the right moves and prediction. For Example, Predicting a braviary, Roselia can toxic it on the switch. If the braviary is adamant and not scarved, roselia can 1-hit KO it with Venoshock. (Did the calc) Sawk gets outsped if its adamant and not scarved, and gets 1-hit KOd with Leaf Storm. If it is scarfed you can predict the switch in, cotton spore, and one hit KO.
Timid Nature is there for outspeeding Adamant Sawk and Braviary. So yeah
Just to give you an Idea of how amazing this thing is...
252 SpA Life Orb Roselia Leaf Storm vs. 240 HP / 0 SpD Musharna: 259-305 (59.81 - 70.43%) -- guaranteed 2HKO
252 SpA Life Orb Roselia Venoshock vs. 240 hp/ 0 SpD Musharna 55-66% Guranteed 2 HKO
Roselia can beat Musharna if you play right.
252 SpA Life Orb Roselia Leaf Storm vs. 4 HP / 0 SpD Gardevoir: 220-261 (79.13 - 93.88%) -- guaranteed 2HKO
If life orb, stealth rocks, or any thing of that sort, this guy is done.
252 Life Orb Roselia Venoshock vs. 252 hp 4 spD Gurdurr: 75-92% Guranteed 2-hit KO
252 SpA Life Orb Roselia Leaf Storm vs. 252 HP / 4 SpD Eviolite Gurdurr: 286-337 (76.47 - 90.1%) -- guaranteed 2HKO
So Yeah. My second idea. My first one was taken ;_;