I may sound insane but....
Midnight Lycanroc, Nidoqueen, and Zebstrika
Lycanroc: hard carried me through the first 3 gyms you be thing the second gym is a fighting gym and yes there is a move called counter and he one shot everything
Nidoqueen: not nedoqueen exactly but and pokemon with sheer force and moves with extra effects my nidoqueen with poison jab and earth power
Zebstrika just great fast attacker