nothing
No, mew can't be caught in leafgreen It can only be caught in emerald after going to an event
Nothing significant happens if you beat the Elite 4 three times in Pokemon Diamond, unless you include acquiring huge amounts of money and leveling up your Pokemon a very good amount.
The only island you can go to is the tenth. After you battle the Elite 4 500 times, the SS Anne will come back and take you to the tenth island.
I got lugia by using a Game Shark. I also got a lugia by trading him from the DX gail of Darkness gamecube game.
It doesn't matter how many times you beat the elite four, celebi is not going to just appear.
it means you suck at Pokemon and have no life to try 20 times
After 20 wins, your rival's Pokemon level up.
Uhm.. As many times as you want to i guess
Only once
beat the elite four 12 times and you will find her in the cerealian cave
yes you can ive done it personally
the secrt is if you get all of the signs you get a dioxis after going to elite four 10 times
nothing happens.
Then you beat them 100 times and win :)
beat elite 4 5 times then beat 30 different trainers isn't that good
i heard that you have to win the elite four 12 times and then go to the place you found mewtwo and it would be there.
absolutely nothing.