Actually, the surprise attack of that fist made of evil energy was rather good.
But thanks to Song Shuhang's timely reminder and the fact that Branch Elder Gu Wu himself was vigilant, the latter was able to react when the fist was around ten meters away from him.
"Ah!" the branch elder shouted in a grave tone and waved his seven arms, aiming at that fist made of evil energy.
There was a round hole in each palm of Branch Elder Gu Wu, and viscous black-green liquid shot out of these holes. This viscous liquid possessed powerful corrosive properties, and when it came in contact with that fist made of evil energy, they both canceled each other out.
Not even that fist made of evil energy was able to resist the corrosive viscous liquid. During the time it took the fist to cover ten meters, it had been corroded until it reached the size of a football, and was then crushed to pieces by Branch Elder Gu Wu's foot.