I'm currently at the Burned Tower in HeartGold and I'm ready to let Raikou, Entei, and Suicune run, thus I have come to the point where I have to RNG the two. I've never RNG'ed in Generation 4 before and I don't know where to start with the dogs. Can anyone explain how they did theirs? I also need to be able to RNG Latias when the time comes, so there could be 3 roamers on the field at once. I just have no idea where to start on them. I want to RNG for IVs and nature only.
If I don't want to RNG these guys right now, can I just release them now, KO them later, and defeat the Champion to re-spawn them again when I'm done with the entire game?