Esther - The Watcher Trilogy, #1

When The Watcher dies and the demon arrives, the world will be tested again. Mahilde is the last of an ancient race who harness the power of the Earth but she is waning in a world almost devoid of magic. Her task is to protect the child, the one chance against the darkness, but she cannot do it alone. She finds Malcolm, an ageing mercenary who cares for nothing but coin, and Willich, a hopeless drunkard who longs for his own death.
With these two she must spark a rebellion, for the demon Morbus has turned monarchs to his will and their populations into mindless fanatics. Esther is book I of The Watcher Trilogy, a fast paced adventure in the highest tradition of heroic fantasy.