Ive watched PIMPNITE's videos and tried to imitate his magikarp sweep, so I bred for an adamant, 31 iv on attack and speed magikarp. I maxed out its attack and speed ev too.
Then on the battle I set up stealth rock and got smeargle to pass belly drum to my magikarp. So after getting hit and survivong with 1 hp because of focus sash I used flail. But the problem is the flail didnt do much damage. And wasn't even able to OHKO anything, my opponent didn't even set up defensively.
Am I missing something here?