"the Saga Of Darren Shan" (books)
This book is about a 14 years old guy who became a vampire to save his friend. The friend wanted to be a vampire but a man named"mr. Kerpsley"told him that he couldn't be a vampire.
When Darren became a vampire by mr. Kerpsley to save his friend, the friend got angry, really angry. He thought:"I wanted to be a vampire, now Darren is a vampire!? I should be. Not him!"so he tries to kill Darren and mr. Kerpsley..