The Fourth-Rank Defensive Formation was still shaking violently, under a fierce assault.
Wu Tao spread out his Divine Sense, letting it fall on the four Evil Spirits outside the Fourth-Rank Defensive Formation. In the Origin Spirit Secret Realm, the aura on Origin Spirits was extremely pure, and it even smelled fragrant, making them highly attractive to Nascent Soul Realm cultivators.
But they were just as attractive to Evil Spirits, so Evil Spirits fed on Origin Spirits.
These four Evil Spirits radiated an evil aura. Their entire bodies were pitch-black, their physiques even sturdier, and they had faces—faces with savage, hideous features, as though piled up from countless strands of resentment.
With a preliminary sense of the four Evil Spirits' auras, there were two Level 9 Evil Spirits, comparable to Nascent Soul Level Nine, and two Level 8 Evil Spirits, comparable to Nascent Soul Level Eight. But Evil Spirits were vicious, and their combat power far exceeded their actual level.
However, even a Level 9 Evil Spirit comparable to Nascent Soul Level 9 could not possibly reach the combat power of the Spirit Transformation level. Wu Tao naturally was not worried that he could not beat them.
Evil Spirits were wicked things. When they encountered Origin Spirits, they attacked and devoured them; when they encountered cultivators, they also attacked and devoured them. Logically speaking, Wu Tao's Fourth-Rank Defensive Grand Formation should have been able to shield his cultivator aura so the Evil Spirits would not sense him, but since the Fourth-Rank Defensive Grand Formation stood in the void, it was possible these four Evil Spirits had bumped into it while traveling.
The Fourth-Rank Defensive Grand Formation had blocked their path forward, so naturally, these four Evil Spirits were attacking the Fourth-Rank Defensive Grand Formation with all their might.
Wu Tao's Fourth-Rank