Instead of feminizing you personally, this curse would create a second persona inside your head. This persona would be a normal, average girl about 10 years old, would have the memories of always being a girl, would act like a girl, talk like a girl, have a girl's name, and be one in all ways. At first, this persona would only 'speak' to you in your head, making observations or suggestions lke any 10-year old girl. However, every week after listening to the curse, the persona would age one year, until she is the same age as you. Each week, when she grows a year older, she will also act like a girl of that age. So, in five weeks, she will act like a fifteen year old girl. Also, as she gets older, she also gets stronger inside your head. Over time, she will be able to influence your actions, take temporary control of your body, slowly alter your body to look more like a girl, influence how you speak and act, and even take control of your body away from you entirely. Eventually, you would become weaker and weaker, eventually turning into a 'voice' yourself, while the girl would take over entirely.
