Your body is not merely a vessel for your Soul. It is an integral part of your being. Your Soul can evolve with your body, granting it the same level of defense as your physical body. Your mind, body, and Soul are one.
Your evolutions can adapt and learn from strange and esoteric forces and use them to your advantage. In time, you can even use and evolve far beyond the original holders of your copied powers and the you of the past.