If an erotic book is particularly dark, as Debt Inheritance #1 is, including non-consensual sex slavery (or the very most dubious of consents), with physical violence to the heroine / victim, I personally need an ending I can live with - some justice, some victory. 
 If the book is part of a series, each book should tie up some plot threat in a way that provides some relief from the abuse. Perhaps others will find the perils our heroine is in at the end of book 1 "relief." I did not. I will grant that Ms. Winters does have the heroine achieve a small mental victory (which will probably be sufficient for many readers). I further grant that her end might have be sufficient for me on another day. Today it wasn't. 
 Ms. Winter is creative. The series has several books, so if you like longer novels, those with lots of detail, you may well enjoy Debt Inheritance. 
 Another problem I have with Debt Inheritance is that I like relatively strong, intelligent, sassy heroines. She isn't, IMHO. 
 My disclaimer: I bought the book, I don't know the author and I wasn't asked to review it.