After absorbing a large amount of souls and Death Energy, the Crystal Skull got hotter and hotter, releasing black flames. It vibrated more and more frequently and strongly. Not long after, it gave out bursts of buzzing sounds, drawing the attention of Yang Ling.
Aye, Dark Soul Fire?
Looking at the abnormal changes in the Crystal Skull, Yang Ling sat cross-legged on the ground in puzzlement, sensing in detail its weird changes. Even though he had already used Blood Essence and Dark Soul Fire to recreate the Crystal Skull, he was far from mastering its secrets and mysteries.
With every corpse that fell, its soul would turn into a wisp of black thread that was hard to see with the naked eye and was absorbed by the Crystal Skull. The Death Energy near the door, which nearly suffocated the Troops, also turned into wisps of black threads and was absorbed by the Skull.