What should I name my book?

It's about a girl who has amnesia and she lost the first 15 years of her life. She's now 17 and she only has memory of the last two years. Then she always has a dream in which she is trying to defend a rock which she later discovers it's called an Arcanum. She also hears whispers which are actually the voices of the dead souls her sister kill. Then later, she discovers that she did not accidentally lose her memory but it was wiped out by someone using magic. And she also finds out she's a witch and then she is transported to an alternate dimension where she is taught to control her magic by other witches. She also learns that there are in the middle of a war although there is a false truce at that moment. And also she was the last person to be seen with the Arcanum. So the highest Battlemage, who is her father, begins to hunt her down. Intending to gain the Arcanum by ALL means possible even if it meant killing her.