Plenty of cards received their respective errata recently to transit the game and its cards into the Link-Summoning phase. While plenty texts were changed to remove ambiguity and provide a distinction between Main Monster Zones and Extra Monster Zones, one card received a changed that completely changed the way it is supposed to work.
Discard 2 cards from your hand. Select 1 face-up monster and flip it face-down, but do not change its battle position.
Current (new) effect:
Discard 2 cards from your hand. Select 1 face-up monster and change that target to face-down Defense Position.
Previously, Darkness Approaches' unique effect gave birth to a one-of-a-kind scenerio whereby a monster can be in Face-Down Attack Position. It is notable for being the only card in the entire history of the game to be capable of achieving this outcome, similar to how Toon World holds the distinction of being the only card in the game where it has a cost, but no effect.
While there aren't any mind-blowing strategies associated with it, it does present an interesting situation and make for an applicable test question to test a player's knowledge of the game.
Is there such a thing as an illegal Battle Position?
Players who do not know of this effect would of course, answer it as yes, and present Face-Down Attack Position as an example.
With this errata, an illegal battle position can exist, as Face Down Attack Position is now illegal.
Long before Book of Moon became a card, Darkness Approaches was used in Empty Jar decks. Now, it is a mere relic of the past, as Book of Moon is now Unlimited, can achieve what it does, with no cost and wider window of usage.
So... Hello Darkness My Old Friend?