I wish to know a god-forsaken challenge other than the Black Tower I can face! I've beaten Cynthia and N. Should I then face Alder then Challenge the Elite Four and the Champion again?
Beat the Elite 4 with Pokemon with the same type (ex: all 6 Pokemon are just fire types). Bring along some low leveled Pokemon with one same type with you for a challenge. Not only will you get stronger, you also get a medal for each type.