When Gu Ding returned to the spaceship with his will and found the main cabin empty, he knew that Lilliath and the rest had gone back to their own cabins to cultivate.
The purple energy crystals he had obtained from Elizabeth were of high quality. The reason why they needed the Energy Crystals were that they were the main raw material required to the Dark Sectors' black crystals. After some composition analysis, Neptune managed to come up with a method to make the black crystals along with some added improvements. For some of the easily procured materials, he had already asked Biggie and the others to help him get them. As for the other materials that were not easily procured, he managed to acquire them from Elizabeth. Therefore, as soon as he got the materials, Neptune contacted Robert and asked him to help him make it.
