There should be some dark or alternative universe fanfics that might explore such a disturbing concept. However, this goes against the nature of Ahsoka's character in the main Star Wars canon. In the official lore, Ahsoka is a heroic figure, so such fanfics are often considered non - canonical and extreme interpretations.
Maybe some writers want to explore extreme character deviations. They might be interested in creating a shock factor by making a beloved character like Ahsoka do something so heinous. It could also be an attempt to explore a very dark, alternate universe where all the good characters turn bad.
One common storyline could be Anakin's struggle with his darker side while interacting with the younglings. For example, in some fanfics, Anakin might be forced to protect the younglings from an external threat, which tests his loyalty to the Jedi Order. Another storyline could involve Anakin teaching the younglings, which shows his relationship with the next generation of Jedi. There are also fanfics where the younglings sense Anakin's internal conflict and try to help him, adding an interesting dynamic to the story.
One great Ahsoka and Anakin fanfic is 'The Apprentice's Journey'. It delves into their relationship during their time as master and apprentice. It shows Anakin's complex emotions towards Ahsoka, his pride in her growth as a Jedi, and also his protective instincts. The story is filled with action scenes that they face together, and the character development is really well - done.
One great Ahsoka fanfic is 'Ahsoka's Journey'. It delves deep into her post - Clone Wars adventures, exploring her character growth and her relationships with other Star Wars characters. Another good one is 'Ahsoka and the Lost Jedi'. This fanfic focuses on Ahsoka's search for lost Jedi knowledge and how she uses it to face new threats in the galaxy. And 'Ahsoka's Redemption' is also popular, which tells a story about her trying to make up for past mistakes and find her true place in the Force.
Her opponents could be the Separatist forces. Umbara was a planet involved in the Clone Wars, so it's likely that battle droids and their commanders would be her foes. They would be trying to gain control of Umbara's resources or strategic locations.
In some versions, it could be a former ally who has been corrupted. This character, once on Ahsoka's side, has now turned against her due to some external influence or personal greed. Their knowledge of Ahsoka's strengths and weaknesses would make them a formidable opponent, and they could be the one to cause her death.
It could potentially be about the younglings in the Star Wars universe. Maybe it focuses on their training at the Jedi Temple, their daily lives, or their experiences during the events that unfold in the Star Wars saga. However, without more context, it's hard to say for sure.
Anakin Skywalker is a popular choice. Their relationship as master and apprentice in the Star Wars universe provides a lot of material for fanfics. Another popular character is Rex, as they have a history of fighting side by side in the Clone Wars.
Ahsoka can be developed by showing her growing understanding of Anakin and Padme's relationship. For example, she could start off being a bit naive about love and then gradually realize the depth of their connection. Also, her skills in the Force could be enhanced through her experiences with them. Maybe she has to face a powerful enemy alone while protecting Anakin and Padme, and this forces her to dig deeper into her Force abilities.