It was a manga or manhwa that went like this:
There was a guy drinking his coffee and giving a backstory of how he got stuck in this thing. And how he knows how the book or timeline goes.
Then he checks and realizes on the newspaper that the hero and hero’s party die. Then later on, the guy finds a young boy who was the son of a prostitute who is really smart and he was able to make predictions to make himself very rich.
Then after that they went and found another person who always keeps his eyes closed. When opened the eyes give out a 'demonic killing intent' thingy. The kid always was passive and so didn't want to have to go along with his killing intent.
The Main character stops him from going mad cause the other irrelevant guy was trying to kill the demon eyed kid’s sister. Afterwards they went to a yakuza-like place which they find another companion but the companion is a woman and the daughter of this big group.