beat the elite four 900 times
Use Sweatin'.
In Ruby and Sapphire yes you need to beat the Elite Four first, but in Emerald you can catch Raquazza before or after you beat the Elite Four.
You need to beat the elite four before you can get Zekrom.
No
You need to beat the elite four and then beat the Pokemon league champion
You need to beat the elite four and get the national dex.
You don't need pokemon, you just need to beat the elite four and have the national dex (which you should get after you beat the elite four, because they have kinda rare pokes)
yes you just need to beat the elite four and champion
Yes you do.
no
yes
no