“Whether by the sword or the slow decay of time Shining Armor will die. And there will be no comfort for you, no comfort to ease the pain of his passing. He will come to death, an image of the splendor of the kings of Ponies in glory, undimmed before the breaking of the world. But you, you will linger on, in darkness and in doubt, as nightfall in winter that comes without a star. Here you will dwell, bound to your grief, under the fading trees, until all the world has changed and the long years of your life are utterly spent.”

Ah yes, the inevitable side effect of immortality.