Trepang2
49 Achievements
GOG
50 shades of burnt
Destroy 1000 cultist books
19.4%
How to unlock the 50 shades of burnt achievement in Trepang2 - Definitive Guide
This one should come naturally by just playing through Jorvik Castle. There will be plenty of bookcases that will catch any stray bullets and explosions etc from you or the cultists.