While Shirong was cultivating, Lin Wu decided to finally start refining his spirit sense. He first went over the method in his mind before getting ready. It was mentioned that one needed to have a calm mind and great focus to be able to successfully refine their spirit sense.
According to what Lin Wu had learned, spirit sense was nothing but tendrils of spirit qi which were made by linking the wisps of spirit qi together and binding them together with the will of the cultivator. Lin Wu didn't understand how the will would bind it, but it was mentioned in the technique that the will of the cultivator naturally imbues their spirit qi.
But this 'will' is quite dissipated and needs to be linked properly for it to control the spirit sense tendril. Lin Wu withdrew a wisp of spirit qi from his core and brought it to float outside his body. This was the very first step and took most cultivates weeks if not months to achieve.
