I think we can all agree the second Gym Leader is hard. No matter what Pokemon you have, it's nearly impossible. Here's what I've done so far to beat it:
I have gone to Slateport, and delivered the Devon Goods.
I've caught Pokemon like Minum and Oddish to help.
I've defeated almost every person in Slateport and Dewford.
And I still cant beat him. Does anyone have any strategies to easily beating him?