Since Foltan was ahead and Pharan was behind, they thought that Jimage's group would escape through the sides. Because of that, both of them had more or less positioned themselves to cover those escape routes. Also, they kept their full attention on Jimage and Rui, who had the highest cultivations on Jimage's group. As for the rest of their groups, they kept their positions to prevent them from easily escaping through them as well.
However, they were really taken aback when they saw Krune and Iem attack each of the groups on their own! It was so unexpected that Pharan and Foltan didn't even react. Yet, they were not too afraid of Krune and Iem doing much anyway. That's because the two 3rd and 6th Stages Divinity Realm members of their groups were still there with the others. Considering Krune and Iem's 2nd Stage of the Semi-Divinity Realm, there was simply no reason for them to go help. If anything, they were happy that those two threw themselves into the lion's den.
