Princess of life and death

Once upon a time there was a castle. Deep, deep in wods where no one could find it. In the castle was an all known princess. Princess so powerfull that to her death was just a phase you could be pulled out from. She could control the living and with a snap of her fingers someone could die. Even though she sounds terrifying, she is as sweet as cake. She was very loved by her loyal servants. She sounds nice. But she does want to rule over the world. Just not in a way where everyone would be scared. In a way where there is peace.
Her name is

Sorry for the grammer:-P