One possible motive could be that Clark has been mind - controlled. Maybe some powerful villain has gotten into his head and is making him act against his will. Another reason could be a misunderstanding. Clark might think Kara has done something extremely dangerous or wrong that endangers the world, so in his warped sense of protecting the planet, he tries to kill her.
She may also be forced to defend herself. Given her powers, she could use her super - speed or super - strength to avoid Clark's attacks. And she would probably be hurt, not just physically but also emotionally, because Clark's actions would be a betrayal of their relationship.
It could also be a plot device to create drama. If Clark is acting like an ass, it can lead to all kinds of conflicts and emotional turmoil in the story. It might be a way to test Supergirl's character, to see how she reacts to someone she once respected or looked up to behaving badly. Additionally, the writer might be trying to explore power dynamics. If Clark, who is usually seen as a powerful and moral figure, starts acting in a negative way, it can shift the power balance in the Supergirl - centric world of the fanfic.
One theme could be survival. Given the post - apocalyptic setting of 'The 100', Clark and Madi would constantly be facing threats to their lives. A fanfic could explore how they use their skills and knowledge to stay alive. Another theme might be family. Clark has become like a mother figure to Madi, so a story could revolve around the development of their family - like bond.
It could be related to some sort of power struggle. Suppose there's a power or ability that Sam has that Tucker wants, and he believes the only way to get it is by getting rid of Sam. Another possibility is that Tucker has been influenced by some dark force or entity that has compelled him to do this evil deed. This could add an element of the supernatural to the story and explain his otherwise out - of - character behavior.
One possible motive could be political ambition. Maybe Peter wants to take over the emperor's power and position in the fictional world. If the emperor has a lot of control and influence, Peter might see killing him as a way to gain that for himself.
It could be that Alexis is being influenced by someone else. There might be a third character who has their own agenda and convinces Alexis to go after Beckett. Also, Alexis might have some internal issues, like self - esteem problems. If Beckett is constantly achieving things that Alexis feels she can't, it could lead to feelings of inadequacy and then the urge to bring Beckett down.
One possible motive could be a misunderstanding. Maybe the Hunt has been misinterpreted as a threat to Percy's friends or Camp Half - Blood. So in his attempt to protect his own, he takes extreme action.
One possible motive could be jealousy. Maybe Kurt is getting more attention or opportunities in the Glee club that Rachel desperately wants. For example, if Kurt is chosen for a solo that Rachel thought she deserved, it could push her to extreme actions in the fictional world of the fanfiction.
Well, that could lead to a whole new dynamic in the story. Maybe it would change their relationship completely and bring about unexpected plot twists.
In 'Clark Kidnaped Smallville Fanfiction', it could be Brainiac. This super - intelligent being might see Clark as a valuable specimen to study and kidnap him for that purpose. Also, a group of government agents who are afraid of Clark's power and want to keep him under control could be the kidnappers. They might think that by kidnapping him, they can find a way to neutralize his abilities. Additionally, a powerful witch or warlock from Smallville's supernatural side could kidnap Clark to use his powers for their dark magic.