I liked Lana very much. She was really young but she didn't have TSTL moments. She understood when to state her thoughts and when to just follow orders.
Vali was also nice. At the beginning he was just fond of Lana and the growth of his feelings for her was nicely descripted.
Their feelings for each other seemed real and the way they were acting dring the whole story was plausible.
Th heat between them was hot and the the intimate moments were tastefully done.
The pace of the book was also nicely done with all the POV changes. Each character was actin in a logical way.