Felix knew that stance. It wasn't a counter stance. It was the damage accumulating stance that Lindo once used against him in training!
He found it strange that she knew the same technique as Lindo...
But because he knew the technique, he also knew that it would be rather dumb to attack her normally as she would be able to accumulate all of the damage he did to her as energy in her body and unleash it in one destructive attack that was hard to dodge.
In this situation, Felix needed to find a breakthrough point where her guard wasn't up and break her stance.
Thus making her unable to accumulate damage that she could throwback to him.
But how could he break her stance?
What he could see from the short distance away from her was a flawless stance with no openings.
He wasn't sure at all how to break it.