The common currency in the Evil Will World was the Thought Stone. It was said that the Thought Stone was also formed by human evil thoughts and could effectively replenish demon power, ghost power, magic power, and monster power.
The Willpower Stone was also divided into four grades: low-grade, medium-grade, high-grade, and supreme-grade. They corresponded to different cultivators. Some high-grade cultivators basically had no effect when using low-grade Willpower Stones.
In the Twin-headed Demon Snake's nest, Zhu Wuwan had obtained more than a hundred low-grade Willpower Stones. These Willpower Stones could be used to recover and increase demonic power.
