Combination Chakra Nature(s):
The Dark Stye is an advanced chakra nature. the Dark Style is a combination nature of wind and fire-based chakra, it's a none-kekkei genkai nature, so it can be use by anyone. It allows the user to manipulate the shadows from the surroundings, his own, and since it's both wind and fire-based chakra, the user can manipulate any into a powerful densive or offensive Dark Style ninjutsu.
The Dark Style nature is rivaled to the Psychic Style nature, because it's alike look one side of a coin, heads and tails, day and night, light and darkness, you can't have one without the other.