Back on Krune's side, he was in the middle of a battle against two Heavenly Fragment owners. Or better, he was simply dragged into it. Krune was following the flow of Spiritual and Godly energy when he saw those two battling each other.
He decided to ignore them at first, so he used his Tribulation Lightning Layer to hide from Divine Senses. But he didn't expect them to leave behind a Warning Formation. It was like a thin and invisible barrier. It had so little energy that even Krune had difficult to notice it.
But it was too late, both of the cultivators immediately looked at his direction. They thought that Krune was planning to be the mantis hunting the cicada. In the end, the two of them joined forces temporarily to get rid of Krune first.
Krune could have run away, but Light Spirit stopped him.