章 144: Chapter 144: Blood Rain from the Sky

After noon, the temperature in the secret realm began to slowly drop.

The apprentices were each busy with their own tasks, not disturbing each other.

An hour later, Ivan noticed that the dense network of runes underground had quietly vanished, as if it had never appeared before, and he could imagine the network quietly resurfacing the next day.

In his spare time, he tested his Combat Energy.

The penetrating characteristic of Combat Energy was related to some sort of wave, like a human-enhanced version of bat sonar, allowing his Combat Energy to penetrate some objects to "strike the cow beyond the mountain."

After numerous attempts, he inadvertently discovered that he could attach his Combat Energy to the surface of a rapid wood silkworm's body. The Combat Energy would resonate wonderfully with the Spring Bud inside the silkworm, allowing the Combat Energy to exist briefly even after the silkworm flew far away.