It could also be that Anakin has been through a long and arduous journey, both physically and mentally. He may have faced many challenges and finally, when he reaches Obi - Wan, his strength gives out and he collapses. His collapse in Obi - Wan's arms could be a turning point in the story, leading to Obi - Wan making important decisions about Anakin's future or their relationship.
In the fanfiction, it might be that Anakin has been poisoned. As the poison takes effect, he collapses into Obi - Wan's arms. Or perhaps Anakin has just learned some devastating truth about his past or the Jedi Order that shocks him to the point of physical collapse.
Obi - Wan might be shocked at first. His eyes would widen and he'd quickly try to assess Anakin's condition, checking for any visible wounds.
Some fanfictions might explore a situation where Anakin is being manipulated by a powerful dark force or a Sith Lord. This dark influence makes him see Obi - Wan as a threat to a grander plan. So, he kills Obi - Wan as part of this dark scheme, not fully in control of his own actions. And this can lead to a lot of complex emotions and plot developments later in the story, like Anakin's further descent into darkness and how the other characters react to Obi - Wan's death.
In many fanfictions, Obi - Wan might use his deep knowledge of the Force. He could reach out to Anakin through a Force - bond, calming his inner turmoil and guiding him away from the dark side. For example, he might remind Anakin of their past together, their training, and the values they once held dear.
A possible plot twist could be that Obi - Wan was actually faking being turned to the dark side all along. He was trying to infiltrate the Sith ranks to learn their secrets and stop them from within. He lets Anakin think he has succeeded in turning him, but in reality, he is still a Jedi at heart and has a plan to take down the Sith.
A possible plotline is that they go back in time and get involved in an ancient Jedi - Sith war. They could use their knowledge from the future to tip the balance in the Jedi's favor. They might also meet their ancestors or past Jedi heroes and learn from them, which in turn helps them in their fight against the dark side in their own time.
One possible consequence is that the Jedi Order becomes stronger. With Anakin remaining on the light side, his power is added to the Jedi's arsenal. They can better face the threats from the Sith and other dark forces.
The struggle between the light and dark side is also common. Since we know Anakin's fate, fanfictions often play with the idea of Obi - Wan trying to keep Anakin on the path of the light. It's about the internal and external battles they face in relation to the Force.
Well, 'The Unspoken Understanding' is a must - read 'anakin obi wan fanfiction'. It focuses on the unsaid emotions and the silent communication between the two. It beautifully portrays their friendship and the trust that was once there. Also, 'Anakin and Obi - Wan: Parallel Journeys' is really good as it shows their individual growth while still being connected to each other.
In many Obi - Wan and Anakin fanfictions, the theme of mentorship is key. Obi - Wan's role as Anakin's teacher and guide is central. Also, the idea of destiny plays a part. Whether they can fulfill their destinies together or separately is a common plot point. Additionally, the theme of sacrifice is present, as both characters are in a position where they may have to sacrifice for the greater good or for each other.
Perhaps Obi - Wan uses his Jedi skills in a creative way. For example, he could use a Force - related technique that shields Anakin from the influence of the Sith. He might create a sort of Force barrier around Anakin's mind, preventing the dark whispers from corrupting him further.