you use your stongest Pokemon and level them up to 100 and kill you rival to bits!!
recomend me please
No its not an HM in leafgreen.
train your Pokemon that's it.
Beat 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
You have to beat the elite four and complete your pokedex.
The same you can do in Fire Red.Read my answer to that here:What_can_you_do_after_you_beat_the_elite_four_in_pokemon_fire_red
beat the elite four
you catch and train Pokemon fill up the pokedex and beat the elite four
u can beat elite 4 again ., but they has improve their pokemon level . GL !! ^^
Red is the boy playable character in leafgreen you don't defeat him because you are him.