You fully control the NPCs you create.. But the public NPCs like Prof. Elm, his aides, Ethan's mom, Gym leaders and so on can be bunnied only a bit.. For example, you can rp that you caught the professor sleeping, but can't take him with you on a stroll (at least not outside New Bark Town). You can't use them for your own purpose but can rp the way they interact with you.