I Deal with the Eerie Without Breaking a Sweat

Looking for Books Set in an Eerie World, Like Those About a Demon-Suppression Bureau! Eerie, Not Ghostly!

Looking for books like Starting by Castrating Myself: I Can See Hidden Information. Set in a strange world of mutation and cultivation, with the protagonist in an organization like the Demon-Slaying Bureau, practicing bizarre mutation-based techniques.

The Strange and the Chaotic, Faint Whispers in Your Ear, a Global Transmigration with Multiple Protagonists