Rune of the Dark Star

"After a time, some members of the Shadowmoon Clan attempted to use the powerful void-magics of the darkened Naaru, but it caused them to become corrupt, arrogant and to defile the spirits of their ancestors. This act was a direct contradiction of the shadowmoon clan's tradition of preserving the sanctity of their ancestral spirits, so the clan's chieftain outlawed the practice of shadow-magic entirely."