What is the theme in Blood Promise by Richelle Mead?

One important theme in the novel, Blood Promise, is that of love.

Rose loves Dimitri. From the day they met, from the moment they were victims of a lust spell, Rose and Dimitri have fought their relationship. Dimitri is Rose's teacher and they are to be co-guardians of Lissa in the future. For this reason, it is not practical for them to be lovers. However, despite their attempts to fight their love, Rose and Dimitri find themselves drawn to one another over and over again.

When Dimitri is turned into a Strigoi, Rose begs Lissa to heal him. When Lissa refuses, Rose feels that all is lost. Although Dimitri is still alive in the world somewhere, he is no longer the kind, gentle man she once knew. However, Rose cannot accept that Dimitri is dead and just forget him as everyone else has managed to do. For this reason, and because she knows Dimitri would not want to live as a Strigoi, Rose goes in search of him.

Rose gives up everything that matters in her life, her future and her friendships, to find Dimitri. When she does find him, Rose finds it impossible to kill the man she loves. Hence, Rose is easily kept prisoner by Dimitri and he is almost successful in convincing her to become Strigoi like himself. In the end, however, Rose realizes that this is not the true Dimitri and the only kind thing she can do for him is to release his soul from this soulless life. Rose tries to kill Dimitri and only learns later that she failed.