The Darkness Within Us by Tricia Levenseller

When a young widow's hard-won independence is threatened by a half-demon claiming her inheritance , their cutthroat battle for control of the dukedom ignites into a deadly and passionate romance. 

This book contains: alcohol, alternate sexual ideologies, anxiety, blackmail, body horror, death/grief, demonic content, depression, explicit sexual activities/nudity, gore, misogyny, murder, oppression, parental neglect, profanity, prurient behaviors, sex exploitation, sexism (pervasive), sexual dialogue and violence (excessive).