Well to me it depends on a few things. Is this intended to use any Pokemon Video Games at all, if so is it B/W B/W2, Pokemon Conquest. Well based on the outpost/pokemon purchasing system, I think that every person should have a signature Pokemon that they start with by default. It can be any mon except for legendaries because they are to powerful, and can be used later in the campaign/game/series for adding excitement, or for a one time chance of obtaining. This is all I have at the moment I can come up with more with more details given.