Darkness within you can be "awakened" quite simply through meditation. Darkness is not bad nor evil, simply an energy. It is like magic, it is just itself and no matter what labels you attach to it to define it, it shall remain itself.
As for black wings I haven't a clue what you mean by "earn your black wings" however I have my own in the form of shielding and am quite happy only having them as such. If they were physically life'd be much much harder. ^___^ Really just a matter of looking at it.
Also, what *exactly* are these "black wings" supposed to do?