Instructions
Field a Flying- or Psychic-type Pokemon in your first fight with Black Belt Nob. In this fight, he only has one level 20 Fighting-type Pokemon, a Machop.
Use a Flying- or Psychic-type Pokemon in the first rematch. Black Belt Nob will field a level 30 Machoke, also a Fighting-type.
Add a Flying- or Psychic-type Pokemon to your battle party for the second rematch, in which Nob will use a level 29 Machop and a level 29 Machoke.
Use another Flying- or Psychic-type for the third rematch. This time, you will face one level 31 Machop and two level 31 Machokes.
Defeat Black Belt Nob's level 33 Machop, two level 33 Machokes, and one level 33 Machamp with three Psychic- or Flying-type Pokemon of similar levels. This is the final fight --- once you have completed it, Black Belt Nob will stay away, and will leave you alone from now on.