Complex sentence: Even if the body of an angel was destroyed, the Exsphere would also need to be destroyed as well for them to truly die; it was possible to live on in a Cruxis Crystal even after the body of its subject had been destroyed.
Split into simpler sentences: Even if the body of an angel was destroyed, the Exsphere would also need to be destroyed as well for them to truly die. It was therefore possible to live on in a Cruxis Crystal even after the body of its subject had been destroyed.