Mysterious black cocoon of 601

That was a black feather.

When the flowing Blood River encountered this feather, it automatically parted to both sides, unable to submerge it. Just this point alone was sufficient to reveal the extraordinariness of the feather.

Huang Yi immediately controlled Falcon to fly down and grabbed that feather, examining it carefully.

Each barb on this feather was very distinct, orderly, spotless, and not tangled together. Each barb formed a perfectly appropriate curve, as if designed with meticulous care by the creator.

Huang Yi reached out to take the feather and held it in his hand.

No sooner had he touched it than he felt an unprecedented pure dark breath!

It was the most pure dark breath he had ever seen! It even surpassed that from the Demon King's Gate in the Abyss!

Huang Yi was immediately shocked. What kind of creature could possess a feather that emitted such a pure dark breath?