I cannot explain how two souls join. No man or element or god ever could. But you are tied to each other. Because of that—because of your true, consuming, pure love—you will thrive together . . . or you will perish together.“I don’t understand.” I swallowed, trying to make sense of it all.If he hadn’t heard your voice, he’d be fine. But once he aged, however many years from now that might come, you would have found yourself deteriorating then. Or if you had disobeyed Me so fully that I had to kill you, he’d have died in the same breath. You are tied through your souls. Now, what happens to one body happens to the other. And since your voice has taken hold of him, killing him slowly, you fall down with him. Slower, of course, as you are still Mine. But it will consume you eventually, all the same.
~ Kiera Cass
