you will need level 50-60 Pokemon to defeat and try to get each Pokemon type like grass fire ice ground etc
Kyogre
you get all gym badges, strong Pokemon, and go to the Pokemon league. beat all people there.
the Pokemon have levels not you
Its not what its how you control your Pokemon. I beat Steven with my own Pokemon not LEGENDARY Pokemon regular. As long as you train them right it should work out.
fire types beat steal
Pikachu
beat the gym leaders
what do you mean the elite 4 are in the Pokemon league in evergrande city you should be able to beat them if you have good Pokemon
you should have a lvl 50 water type
Fighting and bug type should do the trick
your Pokemon should be at least all over level 40 i beat her with one infernape and wiped her out using flamethrowermy infernape was level 47 when i versed her
The Petalburge Gym uses Normal Type Pokemon so you should take pyschic Pokemon or fighting type Pokemon if you want to beat them quickly.