YOu have to either find them or use a game shark

frist you need to go to the burned down tower and fall down the top hole then you need to find them in the grass it is random

What Type of pokeball do I use?

I found entie out of know where in the middle of grass and you can use a master ball if you want to catch him without him runnin...
P.S. he ran from me right after i threw one pokeball it was a ultra ball

look in the grass. it sooo hard to find it but once u do, u have it on ur pokedex then go find 2 routs that r right next to each other and walk into one and look where it is. if its not on the same route as u then go into the other rout then check ur dex again and keep doing that until he's (or she...its not gender marked) in the same rout as u. then use a whole bunch of repels and walk around in the grass until u find him. then put him to sleep or use scary face or anything so he cant run away and attack him until he's close to fainting. then use a bunch of ultra balls and great balls. and if u still have ur master ball u can use that on ur first encounter. but it WILL help if u give the master ball to a pkmn and clone it a whole buch of times then u can use them on suicune, entei, raikou, lugia and ho-oh.