[Bungou Stray Dogs Kunita] Blue Queen and Golden Knight

Trying to expand on the "Cangqi Incident" mentioned in one volume of the novel. There are a lot of private settings. It is not very similar to Kotai's Kotai-mon, but please believe me, it is really a Kotai-mon (what am I talking about ORZ) Concept: What color will the soul of Kunikida Doppo look like when it burns?