One great 'Jason Todd and Damian Wayne' fanfiction is 'Brothers in Arms' which explores their complex relationship in a really interesting way. It doesn't have any lemon elements though. Another one could be 'The Dynamic Duo Redux' where their characters are well - developed and the story focuses on their adventures together. There are not many lemon fanfictions about them that are widely known, as their relationship is often depicted in a more platonic or brotherly context in most mainstream works.
Perhaps Jason Todd is being manipulated by a greater enemy. This enemy convinces him to kidnap Damian as part of a larger plan to disrupt the Bat - family. Jason, still dealing with his own traumas and insecurities, falls for it. He takes Damian, not fully realizing the implications of his actions. As for Damian, he would be a feisty captive, constantly trying to escape and fight back against Jason.
One possible scenario in this fanfiction could be that Jason Todd and Damian Wayne initially have a tense encounter due to their different upbringings and personalities. Jason, with his more rough - edged past, might be skeptical of Damian, who was trained in the League of Assassins. Talia could act as a mediator or perhaps have her own motives for bringing them together. Maybe she sees potential in their combined skills for some greater purpose she has in mind.
Since there aren't a ton of these types of fanfictions, but if there were, a common theme might be the exploration of their forbidden or unexpected attraction. Given their complex relationship in the original comics, it could be about how they overcome their initial animosity to develop feelings for each other.
Jason Todd, who was brought back from the dead and has a bit of a grudge against the Bat - family at times. And Damian Wayne, who is trying to prove himself worthy in the family. In this fanfiction, their interactions drive the story forward as they are the central focus.
One common theme is redemption. Jason has his troubled past as the Red Hood, and in many fanfictions, Damian helps him find a path towards redemption. For example, in some stories, they work together on a mission that makes Jason see the value of his place in the Bat - family again.
Jason and Damian could have a battle of wits at first. Since Jason has his own sense of justice which has been shaped by his traumatic experiences, and Damian has the strict discipline of the League of Assassins. Talia might be torn between the two, as she cares for Damian as her son and has a certain relationship with Jason as well. Maybe she tries to make them see each other's points of view.
They might initially clash due to their different personalities and past experiences. Damian is more disciplined and trained from a young age, while Jason has a more rebellious streak. In the fanfiction, they could start off fighting but then gradually come to understand each other as they realize they both have a common goal of protecting Gotham in their own ways.
Maybe a scenario where they start off as rivals in the fanfiction. Jason resents Damian for replacing him in a way, and Damian sees Jason as a wild card. But as the story progresses, they come to understand and respect each other's values.
The situation could escalate into a full - scale war within the Bat - family. Some might think Jason is completely in the wrong and needs to be stopped by any means necessary, while others might try to understand his motives. Meanwhile, Jason has to deal with a very young and unpredictable Damian. Damian could try to escape on his own and get into even more dangerous situations in Gotham, which would then force Jason to either help him or leave him to his fate, which would further complicate the already messy situation.