The Smash Bros. series lacks more female characters, so one of the best options is to add a female trainer with a different set of starter Pokemon depending on the region the trainer's from/its popularity aside from Gen 1. Dawn is considered to be the most popular representation of the series, making her, and a Sinnoh set, which will be Piplup, Grotle/Monferno, and Torterra/Infernape, an obvious choice for the job. However, because of Iris and her rising popularity, Dawn's chances at appearing in Super Smash Bros. 4 are slim.