Pikachu isn't really even that powerful with a Light Ball. Basically anything with a Life Orb does quite a bit more damage. It's pretty bad, that I actually would recommend Eviolite over it just because of how bad Pikachu is. The only way it can be decent is on a Triples team where it is faster than anything on your opponent's side, and Pikachu's allies both know Discharge and are faster than him. He gets two special attack boosts from the Discharges, and then Pikachu uses Discharge which would probably hurt quite a bit.