Witches poem the first witch to turn says it as her first spell chasing the other witches to come to the town she lives in. They came without the knowledge they were summoned and some whose powers hadn't even developed yet were awakened the very next day.
In Bella yin and yang is very important. Usually you want to be yang. Because in Bella yin is the rich, noble, and high standard people. But if your yin your usually poor, sad, and have very few children or even none.