One possible plotline could be Anakin having to re - learn the ways of the Force as a child while also dealing with his past memories. Another might be how the other Jedi react to this de - aged Anakin, whether with suspicion or a sense of protectiveness.
Yoda would be another character. As one of the wisest Jedi, he could sense the strange situation with Anakin and offer his unique perspective. He might be more patient with a child - like Anakin, teaching him important Jedi lessons and trying to ensure that Anakin doesn't go down the same dark path as he did in the original timeline.
It could be a new and powerful dark side user. This character might have emerged from the shadows, having trained in secret, and their sole purpose is to take down Anakin as he is seen as a threat to their plans for galactic domination.
It could be the Separatists. They might see Anakin as a valuable hostage to use against the Jedi and the Republic. His skills as a Jedi Knight make him a prime target for them to gain some sort of leverage in the war.
In the fanfiction, Anakin may use his sense of humor to cheer Ahsoka up. He could make a light - hearted joke about the situation. For example, if she's upset about a mission gone wrong, he might say 'Well, at least we learned what not to do next time, right? And that's a victory in itself!' This would make Ahsoka see the positive side and feel better.
There are also fanfictions where Anakin gets hurt in a ship crash. The ship could be attacked by enemy forces, and when it crashes, Anakin suffers various injuries like a head wound and broken ribs.
One possible plot development could be that his friends immediately launch a rescue mission. They might use their unique skills and resources to track down the kidnappers. For example, if Obi - Wan is involved, he could use his Jedi mind tricks to interrogate possible informants in the underworld.
The Padawan could be a young alien from a species not often seen in the Jedi order. Maybe an amphibious species that has a different way of sensing the Force due to their unique physiology. This would make for an interesting dynamic as Anakin would have to adapt his teaching methods.
One possible scenario could be that he is killed in a lightsaber duel by a powerful Sith opponent. Maybe this new Sith has some secret technique that Anakin couldn't counter.
There is no such appropriate fanfiction. In the Star Wars universe, which Anakin belongs to, there are certain values and moral codes. This kind of plot would completely shatter the integrity of the story and the characters, and it's not something that the fan community or the general public would tolerate.