Intense, wonderful, exhilarating. It's going to be one of those epic anti-heroes books in the mm sphere. There's a "before" and an "after" them, just like it was the case for Special Forces - Soldiers, The Hell You Say (or more accurately, the Adrien English series) and Captive Prince: Volume Two. If you like anti-heroes who redeem themselves, if you liked Dan and Vadim even though you wanted to shout at them for hurting each other so much, if you liked Jake in Adrien English, even though you thought he deserved to roast in hell for his treatment of Adrien, and if you liked Laurent in Captive Prince even though he was a "cast iron bitch" who didn't deserve to even polish Damen's shoes, then you might just love Bitter Legacy. 
 Like the 3 other books/series mentioned, the characters are complex and imperfect, but they win you over big time in the end. So the happy end seems impossible, until it happens. The characters don't get it easy, fuck. They work for it like the damned. So the book is a long painful journey of love and tears and sweat. 
 I don't even know if this review makes sense. Just read it if you liked the 3 books/series mentioned. Then please drop me a message of something to let me know. I'll hunt all the reviews to see if people had a similar emotional response to this book. 
 I checked and it seems like it's the first book (or MM book) from Dal Maclean. I hope another MM book is in the works because, seriously, this author simply rocks.