Zhou Tian's consecutive attacks on the Monster, although unable to inflict damage, rendered the Monster unable to strike at Zhou Tian. If such attacks continued over time, they would eventually cause certain damage to the Monsters.
"You can't harm me, but I can wear you down to death," Power of the Domain has its limits, and with Zhou Tian's aggressive method, it was clear that the King Level Boss couldn't outlast Zhou Tian in a battle of attrition. Thus, even though the Monster seemed formidable at the moment, if it came down to the wire, the victor would undoubtedly be Zhou Tian.
Seeing matters develop in such a manner, the Monster, recognizing Zhou Tian, obviously had some reaction.
