Well, yes, but that's useless. If you give an everstone to a the female pokemon or ditto when you breed with the other pokemon, hte female/ditto's nature has a 50% chance of being passed to the baby, saving you lots of time. For example, You have your female bagon w/ adamant nature and horsea with any nature. You give bagon the everstone, and there's a 50% chance the baby will be adamant.