Hoo boy, a classic case of what I like to call "legendary ass-suckage."
Brave Nature could be better, but it's manageable I suppose since it beefs out your Attack stat nicely. Here's what you can do:
Electivire @ Choice Scarf/Expert Belt/Muscle Band
Brave
Motor Drive
- Thunderbolt/ThunderPunch
- Ice Punch
- Earthquake
- Brick Break/Flamethrower
Simple set really, and about as good as it gets for Electivire in all honesty, but then again if Earthquake + Outrage + Fire Blast + Swords Dance is the one set to rule them all for Garchomp, Electivire can get good mileage with this one set also. Thunderbolt works very nicely at catching out Skarmory and Forretress who would otherwise be able to slow you down a bit , although Flamethrower would work better against Forretress and it is definitely more threatening to you than Skarmory is since it gets Earthquake vs Skarmory's Brave Bird - you do the math. Ice Punch gives great coverage alongside your Electric STAB attack as does Earthquake, and although Brick Break grants better coverage than Flamethrower from what I know, Flamethrower's surprise value could catch foes like Steelix and Forretress out if they're not careful, and assuming your Sp.Attack stat is high enough (if it's considerably over 200, that should be enough.) Item is personal preference - Choice Scarf has very high surprise value and can steal a KO out of nowhere for you, and Muscle Band and Expert Belt should need no real explaination.