Evil Emperor's sudden increase in speed and his silent attack could indeed catch someone off guard. There was practically no one who could catch up to Evil Emperor's movement speed with their eyes, and he was silent when he attacked. In fact, no traces of his attacks could be found. Even Happy was surprised.
However, while Evil Emperor could be fast enough to fool the eyes in close-quarters combat, he could not hide from spiritual senses.
During the critical moment, Happy quickly activated Petite Dragon and ingeniously avoided Evil Emperor's ruthless attack.
At the moment the afterimage he left on the spot was pierced through, Happy keenly noticed that Evil Emperor had seized air, and during that moment, an astonishingly powerful force seemed to have pierced through the air before it let out a loud crack.