Nah. That specific Marowak is the ghost of a Pokemon, but not a Ghost type Pokemon. So it's an enemy that's not a Pokemon (anymore). Which is an important distinction. "Primal" Dialga is Dialga in a special form. It's still a Pokemon (and Dialga itself is catchable, so an unscrupulous trainer could invoke that form with the right knowhow).In that case, could we add stuff like Primal Dialga considering we can never get that Dialga form as a playable character.