The ethereal crystal was clearly some type of core that Heaven and Earth had nurtured. It even carried resemblances with the energy they had tried to concoct during the final battle, but the major experts in the army recognized it for what it was.
Magical beasts had bodies, and hybrids and cultivators had worlds. Every lifeform that walked on the journey toward power eventually developed cores, and the shattering of the sky had revealed Heaven and Earth's one.
Nevertheless, unlike worlds and other types of centers of power, Heaven and Earth's core didn't carry any innate influence. The rulers had been technically dead since they had strived for a complete rebirth, so their existence contained nothing more than energy and knowledge.