You can beat the Pokemon League it is just one of the harder Leagues than in Pokemon Emerald or Diamond.
you cant
HelloSorry to say but you cant trade Pokemon from pearl to leafgreen but you can migrate Pokemon from leafgreen to pearl via the pal park
you cant fight it again
You can, but you just have to beat all 8 Gyms first.
you cant.
you cant
you cant
A lot
i am very sorry, but you cant...
you have to get it in a event and you cant get it in Pokemon leafgreen or firered
You cant
u cant