Chapter Text
Singularity (特異点,, Tokui-ten?) occurs when two abilities cancel each other out and create something different from either skill. As studied by the Special Division, the singularity phenomenon develops into an unpredictable direction due to a resultant loss of control over abilities. (Surce: Copy paste from BSD wiki)
Atsushi's ability "Beast beneath the Moonlight" allows him to transform into a white tiger,called 'Byakko',who in chinese Mythologie a god is, representing the element metal. He's the white tiger of the west. Before he was in the agency and effected by the ability of Fukuzawa, he wasn't able to controll the ability and always transformed under the Moonlight. And the theory about Atsushi being connected to the book, if it's canon,the book could cancel out Atsushi's ability. As we saw in Stormbringer, It's possible to insert a singularity into someone (Arahabaki/corruption - Chuuya) and remember what Dazai said in Dead Apple? "The headmaster[sic.] had these words for you: 'Compared to what your parents did to you when you were just an infant,this doesn't even count as abuse.'" So what if Atsushi's parents where Experimenting on Atsushi? (Just got this idea:) And maybe Doctor N is Atsushi's dad? Atsushi's birthname is unknown,since he wrote a letter to his favourite author,asking if he can use his name and the author replied and agreed I read it somewhere don't remember where tho). And maybe Atsushi doesn't remember anything,since people only remember Something that happend when they were 5+ years old. So maybe,if doctor N is Atsushi's dad,he could have fused Atsushi with Byakko, without Atsushi ever Knowing. Byakko could be a singularity. Before anyone says "Oh,but Doctor N died in Stormbringer!" In Stormbringer, Chuuya was 16. So during that time, Atsushi would have been 12. Atsushi would have been in the Orphanige during this time. And if Atsushi has a Connecting to the book, it's possible that someone tried to cancel out Atsushi's ability with the book,wich created a singularity. And why would Atsushi be the main character when Chuuya or Dazai have more to give as a MC. So Atsushi is probebly connected to the main plot more than we think. After all,the book plays a big part in it too and the book Atsushi is seen with is according to Asagiri "Something to reasemble Something in Atsushi's life" I think if I remember correctly.