Kai Syaoran used a movement art and moved away from Huo De and his tribulation.
It was not that Kai Syaoran was afraid of the tribulation. He only found that the cost outweighed the benefits. To interfere with the tribulation and kill Huo De, he would have to go all out and this meant using his true power as the Mad Wolf. This would undoubtedly expose his identity and prevent him from getting his hands on the Metal law aspect in the Martial Vault.
Since he could defeat Huo De even after he became a God realm cultivator, he chose to let him do his thing. Kai Syaoran crossed his hands and waited for Huo De to finish. Lightning rained down. All nine bolts of lightning had enough power to kill an Empyrean leaving nothing behind.
Huo De was a truly talented figure. He easily forged his God's body. His entire body was made from lava and it increased to reach over thirty feet tall.