You should use it on Rayquaza, i did and i still have a party of six lengendary pokemon.
You can find legendary Pokemon in Pokemon battle quest in the pokeshop.
beat all the gym leade(not including the elites)and you should be able to unlock finding a legendary Pokemon
no
you cant if its a regular Pokemon the original answerer is right but if it's a ditto and you are facing a legendary you can transform into it for the length of the battle or until ditto/legendary Pokemon faints if it faints during the battle.
All legendary
Lugia
A person can find legendary Pokemon in Pokemon Battle Quest by searching the map and battling other trainers. It is also important to have upgraded Pokeballs.
stupid head
If you count sudowoodo as a legendary then yes
Yes, You need a battle pass and some Pokemon in the battle pass (by completing a few stages) Then You need Wi-Fi Connection Use it and hopefully you connect to someone with legendary then try your best to defeat one of the legendary (I defeated a Groudon with just a Marril) The Wi-Fi person may want to have your friend pass then click yes on the exchange friend pass then hopefully he should say yes 2 then if you get his friend pass with a legendary YOU GOT A LEGENDARY POKEMON YAHOO!!!!!!!!!! P.S: You need to defeat the game then defeat gate way again then you should get battle passes (Defeat other Pokemon trainers with 50 LVL Pokemon)
No their isn't a re battle code for Shaymin I guess your hopes are gone but here's some advice when you battle legendary Pokemon you should save you game right in front of the Pokemon before you battle them that way you don't have to try to battle a legendary Pokemon and then accidentally kill it then you will have the chance to catch it again and maybe this time you will catch the Pokemon you wanted to catch thanks man- josheyman123 though what about pokesav??
if you have Pokemon pearl or diamond you can connect 'em up and send legendarys from your ds to Pokemon battle revolution. :)