So I'm running a Pokemon DnD campaign with Pokerole. Right now, I'm making my region and having it set up so that it makes more sense than the regular games (Trainers have to be registered, you must be 18 before you can become one, and some other things).

The one problem I'm having trouble with deciding on is whether I should make legendaries able to be caught and trained. I know in the games this isn't an issue, but for the world I'm setting up, it'd have to be justified with how someone is able to command such a powerful beast.
I want the legendaries to still be that, legendary. It kind of takes away their status if you can just weaken it down and toss an ultra ball to get it. I want them to be the most grueling capture to ever be attempted, so that the players still see them for what they are.

Also, if I were to make them obtainable, how many should I put in? I have the Regi's right now as part of the regions lore, but I'm not sure who else I should put in.

(If this should be posted somewhere else, just let me know and I'll move it)