Time goes back a few seconds, at the start of the fight.
After Wu Feng summoned the four phantoms, he didn't take action, but stood far away, hiding behind the golden palace.
When he saw Chu Wuyao's transformation into a beautiful monster, he couldn't help but show a hint of wonder in his eyes, but he quickly suppressed those feelings.
He knew that he didn't have much time.
As their summoner, Wu Feng understood that although the four phantoms were strong, it was impossible for them to compete with Chu Wuyao.
During their previous encounter, he had noticed that Chu Wuyao's physical strength was extremely strong, and coupled with the Dragon Slaying Sword, she could match Creation Stage cultivators.
As such, it was only a matter of time before the four phantoms died.
In fact, the reason why he summoned these phantoms was not for them to compete with Chu Wuyao, but to hold her back for a few seconds and allow him to use his trump card.