When I remember that Mori and Kouyou obviously didn't know about Fyodor Dostoyevsky, I always ask myself, if Dazai and his encounter happened before Dazai's and Mori's paths crossed or if he met him during his time the PM, but kept it a secret. +

Fyodor isn't just referred to as a "demon", he also introduces himself as the right of both the gods and the demons. +

Dazai and Fyodor seem so similar in the way they think and perceice the world and life itself, even now after Dazai left the PM. They both are basically trying to "save people", but their methods and their views on humanity couldn't be moroe different. +

Where Fyodor seeks the meaning of his life by giving himself the task by creating his "promised neverland", Dazai always seeked the meaning of life by living on the verge of death. And in the end, Dazai may have been called the demon prodigy in the PM, but +

outside the PM he always has been intrigued by people, who treasure life, like Chuuya, who saved the Sheep, even though they betrayed him. +

Like Ango, who put his efforts into recording the lifes of the deceased after the Dragon Head's conflict, their background their family life outside the PM. +

And of course Odasaku, the man who stopped killing, aiming to become a man, who saves people himself. That's the reason why I clearly see Dazai as more different from Fyodor than the similar and +

I may think that Dazai is also aware of it, since he planned on preparing for Fydor to make his move a long time ago already.