This review may contain a few small spoilers of Immortal Beloved & Darkness Falls 
 This book was just so perfect. I loved every page of it, Cate Tiernan really knew how to wrap everything up without it seeming too happily ever after or even too open ended. She always manages to be realistic in her books no matter their genre. Eternally Yours is my favorite book from this trilogy. The journey Nastasya took together with us was full of laughs, sarcasm, immaturity (mostly from Nasty), character development, great secondary characters, a complex yet hot romance, and most of all magick! I am a huge fan of her Sweep series so I was so glad that I picked up this series. At the beginning I would always compare it with her Sweep series but over time it started building its own distinctive voice and the comparisons stopped. Eternally Yours was the ending all fans of the Immortal Beloved series would want. 
 Nastasya, as usual, is still struggling with coming from a dark family. She is trying her best to stay good however there is always this seed of doubt that she won't be able to pull it off for the rest of eternity. The maturity (well most of the time) with her way of thinking shows us just how much she developed and grew as a character. Her romance with Reyn was also still as complicated as always because of her inability to stick long enough in a relationship to be called a relationship. Also with the addition of River's brothers popping up, Nastasya didn't think she'd be able to take the pressure. I really felt for her. Especially since her worries and problems finally have some importance to them. In this novel Nastasya finally solidifies some semi-friendships from Darkness Falls and actually starts new friendships. This was a definite turning point for her character since she has finally started to care for people, not just trying to impress them like how her friendship with Incy was like. 
 My only small issue is the amount of characters in this series. I honestly, till now, still couldn't keep up with all of them. Solis, Rachel, Charles, Asher, Anne, Brynna.. some of them were memorable but others were not. However I loved that this novel had more magick involved and many of the mysteries and our questions got solved and answered. Usually 400+ novels, like I've mentioned before, tend to drag or have fillers in them. However, Eternally Yours's 458 pages had a purpose toward the main plot and the overall understanding for the readers and the enjoyment level. I inhaled the full novel in three days. Three days that included traveling cross continent and spending hours with relatives and outside. I basically sacrificed my sleep because I just couldn't stop reading. 
 All in all Eternally Yours is really a great conclusion to this series. I am kind of disappointed that this is the end of Nastasya's journey because I just love her to bits. Cate Tiernan is officially one of the few authors I would blindly pick up their book without reading the synopsis because I trust that anything she writes I would love.