Complex sentence: Each Gauna has its core protected by a huge mass of an almost impregnable material known as the, most commonly called "Ena," and once the placenta is shed away and the core is wounded beyond repair, the Gauna's body disintegrates.
Split into simpler sentences: Each Gauna has a near invulnerable core protected by a huge mass of material known as the, most commonly called "Ena". Once the placenta is shed away and the core is destroyed, the Gauna's body disintegrates.