Embora nos sejam dadas dicas ao longo da série, somos informados diretamente no final do capítulo 19 do The Blood Mirror .
With Dazen trapped in his own prison, he is confronted with is most cruel creation: a piece of himself designed to distract his brother. This piece of himself still has all of Dazen's memories up to the split, almost all of which Dazen erased himself by using Black luxin.
Durante essa revelação em particular, aprendemos muito sobre a história dos irmãos Guile. E então, recebemos a resposta explicitamente:
This version of Dazen reveals that Dazen is the Black Prism: "They knew you had to be stopped. You, Dazen, are the Black Prism."