The moment Chiyou manifested his sword, the one that he has never used so far, the Dragon sword, Xiong Delun knew that things are now going way out of hands.
Theia had told Xiong Delun about the Dragon sword, and when the first time when he come to know about the Dragon sword
He was shocked and also amazed at the same time.
Shocked because it's a sword that is related to the First Emperor of heaven so it's not a small thing, and amazed because there is a mortal who can hold the essence of the first emperor of heaven in him.
Theia has told Xiong Delun about the three Emperors of heaven and also that the sword holds the pure essence of the First Emperor of heaven which is the golden dragon.
The sword's ability is to burn down anything, just literally anything was also told by Theia to Xiong Deluna.