"A palatable lie is easily swallowed." 
 Well, damn. I went in with zero expactations but The diabolic swept me off my feet! 
 [?] Nemesis's character arc was A+, her slow discovery of her hidden humanity warmed my heart! (view spoiler)[The only thing that bugged me was how easily she believed the emperor's mother when she tried to turn her against Tyrus. I mean, from page one we (Nemesis included) know that's she's a smart scheming bitch who only cares about herself and then she tells her that Tyrus murdered Sidonia and she suddenly believes her???? why???????? no seriously why????? (hide spoiler)]) 
 [?] I liked how Tyrus was always ten steps ahead of his enemies and how he treated Nemesis like a person and not a possession. He's also a morally grey character and I loved that! 
 [?] Sidonia was... there, I guess. I loved how she only wanted the best for Nemesis and how she constantly encouraged her to find happiness but without Nemesis I found her pretty weak and whiny. 
 I liked Nemesis and Tyrus as a couple but I'm not sure if I still ship them after the ending. (view spoiler)[I mean, I don't think he murdered Sidonia but I want Nemesis to fully believe him, I don't like this "If I discover ten years from now that he did it I'm going to murder him but at least we had ten good years" like ?????? what?????? yeah no (hide spoiler)] 
 I'm surely going to read the sequel but I think this would have worked perfectly as a standalone