The thundering in Xu Fan's mind was echoing in the Sea of Divine Sense within him.
The Sea of Divine Sense, commonly known as the Sea of Consciousness, is formed within the cultivator's mind after reaching a certain stage of cultivation.
After Xu Fan transmigrated, in addition to the countless memories of the Cultivation World in his mind, he also retained the powerful Sea of Divine Sense cultivated through hard work in his previous life.
The Sea of Consciousness is the most precious thing in the Cultivation World, representing the realm of a cultivator.
If a cultivator has not cultivated a Sea of Divine Sense, then no matter how strong their combat power is, Xu Fan could simply release his Sea of Divine Sense to suppress them with the power of his domain, trapping them in an illusion of his making from which they could never escape.
The strength of the Sea of Consciousness also manifests in its ability to resist the invasion of inner demons.