One common theme is Anakin getting physically hurt during battles and his friends or loved ones having to deal with the aftermath. For example, in some stories, Obi - Wan might be trying to save a badly injured Anakin.
There are also themes related to Anakin being hurt by the dark side. Sometimes the fanfictions explore how the dark side's influence is slowly corroding him and causing him pain, both physically and mentally, and how he might struggle to break free from it.
The main themes usually revolve around Anakin's emotional turmoil. His feelings of betrayal, whether by the Jedi Council or others, are often explored when he's in a 'hurt' state. Also, the theme of redemption through pain is quite common. Anakin might be hurting badly, but he tries to find a way to redeem himself. And of course, his physical suffering, like from battles or torture, is also a significant theme.
Another theme could be Anakin's search for identity. In the fanfiction, through gaming, he might discover new aspects of himself. He could be a hero in the Star Wars galaxy, but in the gaming world, he has to build his reputation all over again. This exploration of different identities can be a major part of the story. Also, the theme of friendship often comes up. He might make new friends in the gaming community who are very different from his Jedi comrades.
One common theme is his struggle with being different. As a young Anakin, he has extraordinary powers which set him apart from others on Tatooine. This makes him feel isolated at times, and many fanfictions explore how he copes with this.
One common theme is the struggle between light and dark within Anakin. His internal conflict is often explored in great detail.
One common theme is the battle between light and dark. Given their different allegiances in the Star Wars canon, fanfictions often explore how this dynamic plays out between them. Another theme is the idea of redemption. Ventress, having been on the dark side, could potentially be redeemed through her relationship with Anakin.
One common theme is redemption. Often, the OC plays a role in Anakin's journey towards redemption, either by believing in him when others don't or by showing him a different way of looking at things. For example, in some fics, the OC might help Anakin see that there are alternatives to the dark path he's on.
One common theme is the exploration of gender roles. Since Anakin is male in the original, when made female in fanfiction, it often challenges and redefines the typical gender roles in the Star Wars universe. For example, how a female Anakin would handle the male - dominated Jedi Council.
The theme of hope also runs through a lot of baby Anakin fanfiction. Despite his difficult circumstances as a slave, there's always a glimmer of hope for a better future, whether it's through his own skills, the kindness of others, or the potential he has within due to his connection to the Force.
A common theme is the alteration of the traditional gender roles. Since Anakin is male and getting pregnant, it challenges the normal ideas within the Star Wars setting. There may also be themes related to the power of the Force during this unique event. How does the Force interact with Anakin's pregnancy? Is it a normal pregnancy or something more extraordinary due to the Force? Also, relationships are a big theme. How does his relationship with his loved ones change? For example, his relationship with Padmé might take on new dimensions as they face this unexpected situation together.
The idea of legacy is also prevalent. As Anakin was a very powerful Jedi - turned - Sith and Leia is a strong figure in the Rebel Alliance, their combined legacy is a rich area for fanfiction. Writers might explore how Leia could inherit some of Anakin's skills or how she could redefine the Skywalker legacy in a positive light.