After a timid young adult is saved from armed assailants by a beautiful vampire, he is manipulated and trained by her coven to track down his elusive uncle: the de facto leader of the vampire hunters.

3rd Revision (edit to fix typos)

After a timid young adult, ignorant to the supernatural, is saved by a beautiful vampire from an attack orchestrated by his uncle attempting to eliminate opposition to his rule, they work together to track down and kill his newfound relative: the de facto leader of the Vampire Hunters before they themselves are killed.

I find that your character goals and motivations are not properly defined.
- Between the nephew and the vampire, who is the main protagonist?
- Does the nephew know that his uncle was the one who sent the assassins?
- Why does his uncle want to kill him?

I think that the nephew and the vampire fall in love first and then is caught in between when his uncle sends killers to kill the vampire.

Thank you for the feedback.

The use of the word "manipulate" was a failed attempt to show a similarity to the movie "Wanted". I did not mean that he just goes through the motions of the story with no agency.

His uncle sent the armed assailants to kill him. His stakes and motivation are at first survival.

The timid nephew and beautiful vampire are both main characters. The nephew is slightly more main.