At the start, when the Substituter saw Wang Ye moving to strike him, he immediately swapped places with a Double S-Class Meat Shield.
However, just as the Substituter was breathing a sigh of relief, he realized that Wang Ye was still in front of him.
Although he could swap, the crux of the problem was that seeing Wang Ye in two different places caused the Substituter to become somewhat bewildered.
What could this mean?
Was Wang Ye's speed that fast?
Could it be that Wang Ye also had the ability to swap?
Joel, however, didn't know that what he had seen in his original position, the image of the Substituter, was actually just an afterimage left by Wang Ye; the real Wang Ye was right with the Meat Shield.
Psychological warfare.
This Meat Shield was the closest to the Substituter, so when the Substituter was swapping to preserve his own strength, he would surely choose to swap with the Meat Shield nearest to him.