Well, Motor Drive and Agility sure make Eleciball usable. In its own tier.
Emonga @ Lvl 100
Motor Drive (if possible)
Trained with Power Anklet
Item: Magnet (or something that ups electric moves)
Electra Ball
Acrobat
Agility
Volt Change/ Baton Pass
252 Spd
126 Atk
126 Sp.Atk
Completely outclassed by Thundurus/Boltolos who has priority Taunt and FAR better stats.
Well, I wouldn't say completely outclassed, as Emonga has Encore, a possible Electric immunity, and the ability to baton pass speed boosts. I'm not trying to argue that Voltolos isn't a better pokemon overall, which is plain to see, but rather how to use Emonga effectively.
If the cell battery is multi-use, it, when paired with motor drive, could potentially make it a large threat to teams when switched into an electric type attack. Perhaps:
Emolga @ cell battery
Jolly
252 atk, 252 spe, 4 hp
wild charge
aerial ace
quick attack
substitute/ return/ roost
Standard physical attacker set more or less. Wild charge and aerial ace for stab, quick attack for potentially helpful priority. Sub/ return as fillers for 4th slot, perhaps roost might be a viable option too?
Motor Drive negates the Cell Battery's effect, so it's actually useless to have it on.