After he had retreated from the fight, Wu Kong had been dashing from tree to tree but had never gone far and had even managed to get a couple of sneak attacks in. Although he was never given the opportunity to finish his opponents, he succeeded in disrupting their chanting and slowing down whatever ritual the robed-individuals were preparing, all while being chased down by the Yin Body.
Although he hadn't exactly been faring well for himself, the fact he was able to launch an attack every now and then indicated that he at least had enough breathing room to attack and wasn't stuck on defense, but in an instant, everything seemed to be overturned.