One of the main themes could be the struggle between good and evil. Luke Skywalker is typically a symbol of the light side, so exploring his journey towards the dark side would likely involve his internal battle with his own moral compass. Another theme might be the allure of power that the dark side offers and how it can corrupt even the most noble of characters like Luke.
The theme of redemption could also be present. Even if Luke is on the dark side in this novel, there might be elements of his past self trying to break through and find a way back to the light. And perhaps the theme of isolation as he may become alienated from his friends and allies due to his newfound alignment with the dark.
Power dynamics is a key theme. The dark side often represents a different way of using and abusing power compared to the light side. Luke's exploration of the dark side in the novel would show how power can be used for personal gain rather than for the greater good, and how it can change relationships and the overall balance in the Star Wars universe.
Luke's friends from the light side could also be important. Characters like Leia, Han Solo, or Chewbacca. Their reactions to Luke's turn and their attempts to bring him back would be significant aspects of the story. There could also be new characters created specifically for this novel, perhaps some Jedi who were thought to be dead but are actually in hiding and oppose Luke's new path.
One interesting 'Luke Skywalker dark side' fanfiction could be where Luke turns to the dark side after being constantly betrayed by the New Republic. In this story, he might use his newfound dark side powers to take revenge on those who he feels have wronged him. He could form an alliance with remnants of the Empire and become a powerful and feared Sith - like figure in the galaxy.
If Luke Skywalker turns to the Dark Side in fan fiction, one possibility is that he could become a powerful and feared Sith Lord. He might use his Jedi skills in a perverted way, like using the Force to dominate rather than protect. His relationship with his friends would be severely strained. Leia, for example, would be heartbroken and might try to bring him back, but it would be a very difficult task. Han Solo would also be in a tough spot, having to choose between his loyalty to Luke and his own sense of right and wrong.
Maybe in the fanfiction, Luke witnesses something so devastating that he loses faith in the Jedi way. For example, if the Jedi Order fails to prevent a great catastrophe. This could push him towards the Dark Side as he seeks a more radical solution to bring order. He might start using aggressive and unethical means, like Vader did, believing it's for the greater good.
Sure. There's a fanfiction where Luke discovers a hidden Sith temple that has the power to reverse the light - dark side balance in a person. He enters out of curiosity but gets trapped. The temple starts to slowly turn him to the dark side. As he changes, his friends sense it and have to decide whether to try to save him or destroy him, which is a really unique take on the concept.
One of the main themes is the struggle between good and evil within Luke himself. In these fanfictions, we see how his inner conflict plays out. Also, the theme of redemption might be present in some, where there is a possibility for Luke to come back from the dark side. And the exploration of the dark side's allure, like the promise of quick solutions to problems compared to the more difficult path of the Jedi.
If Luke turns to the Dark Side in fan fiction, the story would take a very different turn. The relationship dynamics would be completely altered. His friends like Chewbacca, who had fought beside him, would be in shock. His fall could also inspire other Jedi - in - training to question their own paths. Maybe some would be tempted to follow him into the Dark Side. And the Emperor, if still alive, would have a new tool to use against the remaining Jedi and the Rebellion. He could use Luke to spread fear and chaos, which would be a very different plot from the original Star Wars stories.
His friends like Han Solo and Leia would be deeply affected. They would either try to save him or be forced to fight against him. This would create a great internal conflict within the group that once fought together against the Empire. Also, Luke's turn could inspire other young Force - sensitive individuals to follow the Dark Side, thinking that he has found a better path.
One popular 'Dark Luke Skywalker' fan fiction is 'The Fall of Skywalker'. It explores a scenario where Luke succumbs to the dark side after a series of tragic events. Another one could be 'Dark Apprentice Luke' which shows him as a powerful Sith - like figure. There's also 'Luke's Descent into Darkness' that details his journey towards the dark side in a very engaging way.
Some fanfictions depict Dark Luke Skywalker in an alternate universe where he turns dark much earlier in his life. Maybe due to a different event like the death of Obi - Wan Kenobi in a more brutal way during their first encounter. This changes his entire trajectory and he becomes a powerful and feared Dark Lord, causing chaos across the galaxy.