[yunkaje]

Looking for recommendations on books that dark and grim no sunshine and rainbows, low/questionable morale, anti-hero characters etc.
Any genre is fine, as long as it's fiction.

[.:Kira:.]

You should look for Lovecraft books.

[IndustryCarnage]

Witcher? Could try that.
I like manga more so i'll recommend just that:
Berserk
Vinland Saga
Attack on Titan
Green Blood
And Shigurui 
They have great art and offer just about what you asked for 
Have fun

[yunkaje]

Thank you for your recommendations, I will check them out.