Another thing that bothered me was Shiva's final transformation. She did so without any crystals at all. Up until this point, we've always understood that the greater the quantity of crystals, the more powerful the being becomes. If that's the case, it would have been nearly impossible to freeze the bullets and cause that much damage to a Garlean airship. So if a being can call upon a primal without crystals, is it possible that there's a right and wrong way to summon them?

I'm under the impression that there's much more to aether than we understand. Shiva was very different from other primals, and she seemed to be in control of this energy. Ramuh was also kind and rational seeking justice and judgment, and even in his extreme state the quest story said that Ramuh did not wish to cause harm.