According to Takaya Imamura in a 2005 Nintendo Dream interview regarding Star Fox: Assault, the decision to make Krystal a main Star Fox team member came from Nintendo themselves, following from how it was their decision to keep and also redesign Krystal in the transition from Dinosaur Planet to Star Fox Adventures. Imamura states that there was a bit of arguing over Krystal's personality amongst the development team, with one camp wanting her to occupy a motherly role, and another wanting her to be more like a big sister.

Imamura also said that the decision to keep Krystal around was at least partially because he wanted players to see the characters grow and evolve over the course of the games, and thus there was a desire to acknowledge Star Fox Adventures, Krystal's debut game; he also admitted that it was also because he found her to be an "enticing" character in her own right.