Q: What if the Tarot shows a dark knight?
A: To be honest, Batman is the first thing that comes to my mind when I hear “dark knight”. I’m guessing you mean the Knight of Swords, since in the past Swords have somehow earned a dark reputation as a suite. It makes sense…swords were essentially the guns of their day, the instruments of war, death and destruction.
Putting Swords cards into a more 21st Century perspective, I think of them more in terms of society, and authority. That can be positive (as in keeping the peace, protection of the weak) or it can be negative (as in opression, violence).
By the same token, any knight – or any card at all – can have it’s positive and negative aspects. They are both and neither. “They are both because nature is both” as Lirio said in the 1990s movie “The Craft”. They are neither because positive, negative, light, dark are all lables we put on the things the card simply symbolizes. For example, the knight of swords can sybolize courage and daring. That can be seen as negative, as in assuming too much, or overstepping reasonable boundaries. Or it can be positive as in liberty, facing one’s fears. Each Tarot card is both light and dark – each card encompasses both aspects. Each Tarot card is neither light nor dark because they simply are…they symbolize some idea or state. Whether those concepts or conditions are “positive” or “negative” is something we as individuals project on them.
That being said it is impossible to answer “what if a dark knight shows in the Tarot” is impossible to answer without knowing “who says it is dark?” or “why do you think it is dark, and not simply a knight?”
The cards and their meanings are only part of the equation. The real substance of a Tarot reading comes from people involved through context, judgement, and intuition.