He had two sides to him, a joyous, vital for life side, while he had a side that was dark mysterious and deadly, (Similar to the dual natures of wine).
Dionysus was a god that was born twice in the world, once from his (At the time) dying mother and the second time by Zeus. At a young age the god was murdered by a man named Hera; because of this Zeus put him in a foster family and told the family to raise him as a girl, to fool Hera from finding him again. As he grew older Dionysus would spend his time traveling the world, spreading his ideas and cult. He would have followers worshipping him in the woods.