Demon Emperor (who will save him?)

He was born normal from birth like other kids but as he grew ,his parents started noticing strange things from him ,like growing of claws and fangs,other kids think it Was a normal nails ,unknown to them there was a demon living in him As he grows the demon grows stronger and only manifest at night. He grew up and become the demon emperor Will he ever be free from this demon in him? What will happen when the whole kingdom find out he is the demon killing the people at night?