Machamp, Alakazam, Gyrados, Articuno, Ninetails, Victreebel.
your strongest Pokemon
No its not an HM in leafgreen.
train your Pokemon that's it.
Beat the elite four.
After you defeat the Elite Four.
To open the Elite Four, you have to get all the Gym badges.
just train your Pokemon each to lvl 55 and you should have no trouble
get some good pokemon with good move
Prof oak after beating the elite four.
You have to beat the Elite Four once.
all you have to do is not get beaten
beat the elite four and your starter has to be a bulbasaur