Sabriel. It has a certain directness about it, don't you think? It also gives our heroine a rock star vibe. Think about all the celebrities who only need a single name: Madonna. Prince. Cher. Adele. And Sabriel, with her potent power to walk through Death, is definitely a rock star in her world. Not to mention, the author never reveals Sabriel's last name, or even if she has one. Sabriel herself spends a lot of time convincing other characters to stay on a first-name basis with her too. So, on every level, this one-name title makes a lot of sense.