HOLY FUUUUU THIS IS- THIS IS-

(there are no spoilers dont worry)listen to my theory; this is like the 2nd time that I read this and I think that sangwoo and Yoon b** are actually brothers with the same mom. B**'s uncle once said that his wife (b**'s mother) left him for his brother, and that b** is so similar to his mom. Sanwgoo doesn't kill b** for some reasons, he makes him remind of his own mom, or even has a invisible bound that he doesn't have knowledge about. Maybe sanwgoo mom is even b**'s mom, she had a child (b**) with uncle and then left his for his brother, having another child that is sangwoo. This probably makes no sense