In some fanfics, it could be Anakin's own self - destructive tendencies. He has made so many bad choices in his life that in the end, his own actions lead to his death. For example, if he continues to pursue the dark side without fully understanding its consequences, it could ultimately consume him and lead to his demise.
Anakin in these fanfics may also be shown as a more vulnerable character. The harem might be a support system for him, and through their interactions, his softer side is revealed. For instance, when he is with the female characters in the harem, he might open up about his fears and dreams more than he does in the main storylines, adding new dimensions to his character.
Anakin would be completely shattered. Ahsoka was one of the few people he truly cared about deeply. Her death in his arms would make him question his abilities as a Jedi and a protector. He might feel a deep sense of rage towards whatever or whoever caused her death, which could start to cloud his judgment and lead him down a darker path.
Perhaps a fanfic that delves into the time when Anakin was on the cusp of turning to the dark side. Padme could sense the change in him and tries to prevent it with the help of Luke and Leia from the future who somehow travel back in time. This would create a complex web of relationships and a race against time to save Anakin from the dark side.
Anakin might develop more self - control earlier. Yoda's wisdom and unique training style could help him better understand his emotions and not be so easily swayed by fear, which was a major factor in his fall to the dark side in the original story.
One great Dark Anakin fanfiction could be about his internal struggle. It might show how the dark side slowly creeps in as he faces difficult decisions in the Clone Wars. For example, a story could focus on a mission where he's tempted to use excessive force to achieve victory, and how that starts to change his mindset towards the dark side.
Anakin's character develops a new sense of responsibility. He realizes he's going to be a father, and this changes his perspective on his future. He may start to question his loyalty to the Jedi Order more, as he wants to be there for his family. He becomes more conflicted between his Jedi duties and his family obligations, which is a major part of his character arc in this situation. The pregnancy also intensifies his emotions, making him more vulnerable to the dark side as he fears for the safety of his loved ones.
The fanfic could be set during the Clone Wars. Anakin's dark side starts to emerge due to the stress and manipulation. Padme notices the changes in him. Meanwhile, Luke and Leia are prophesied to be the ones who can save the galaxy from the dark side that Anakin is falling into. It could show how their fates are intertwined even before they are born, with Padme trying to protect the future of her children and Anakin.
Often, Anakin's development in these fanfictions involves him exploring different aspects of the Force. He might discover new Force abilities that were not part of the original story. This new knowledge helps him to dominate in various situations, whether it's in combat or in diplomatic negotiations. Also, his relationships with other characters, like Obi - Wan or Padmé, are often explored more deeply, which in turn shapes his character growth.
The story of Anakin and Padme in fanfiction is important because it can explore the 'what - ifs'. What if Padme had been able to convince Anakin more strongly to stay on the light side? Fanfiction can also show different sides of their relationship. Maybe there were more private, tender moments that weren't shown in the movies. It's a way for fans to get more deeply involved in the Star Wars universe and the characters' emotional lives.