Yuji Itadori is the best Black Flash user in JJK ... "I want Itadori's finishing move," but nothing quite clicked. Eventually, Divergent Fist and then Black Flash were born in that order.

Yuji Itadori awakened after hitting a black flash ... given that the concept of hitting a black flash is quite similar to Divergent Fist, and that is something that Yuji has great proficiency ...