Another motive might be related to power. If Damon wants to gain some sort of advantage or power, he might bite the reader. For instance, if the reader has some special ability or connection, Damon could use his bite to tap into that. Or perhaps he's being influenced by some external force that compels him to bite the reader in order to achieve a certain goal in the complex world of the Vampire Diaries.
One possible motive could be protection. Maybe Damon senses a danger approaching the reader and biting them is his way of marking them as under his protection. In the vampire world, a bite can be a sign of claiming someone.
It could also be out of passion. In many fanfictions, there's a strong attraction between Damon and the reader. His bite might be an expression of his intense feelings, like a very passionate moment that goes beyond normal human interactions. Also, sometimes it's a way to share his vampire nature with the reader, to make them part of his world in a more intimate way.
In some fanfictions, Damon's werewolf bite might lead to a series of events that test his relationship with Elena. For example, Elena could be desperate to find a cure for him and in the process, they discover new secrets about the supernatural world that was previously unknown. The bite could also be a catalyst for Damon to face his inner demons and re - evaluate his actions throughout his long life.
Perhaps in a fanfiction, Damon's werewolf bite is part of a grander scheme. An enemy of his arranges for him to be bitten so that they can take over Mystic Falls while Damon is weakened. Damon has to fight not only the effects of the bite but also this new threat to his home. This could involve a lot of political intrigue among the vampires, werewolves, and witches in the area.
One great fanfiction is 'Damon's Redemption'. In this story, the reader character enters Damon's world and slowly changes his perspective. It's filled with intense emotions and some really well - written dialogues that stay true to the characters' personalities from the show.
The writing style also matters. A good fanfiction uses vivid descriptions to bring the Vampire Diaries world to life. It makes you feel like you're in Mystic Falls. The dialogues should be snappy and true to the way the characters speak in the show. Also, a good fanfiction doesn't deviate too much from the established lore of the Vampire Diaries unless it has a really good reason to do so.
One popular 'Vampire Diaries Damon bites reader' fanfiction is 'Bitten by Damon'. It has an interesting plot where the reader character gets bitten in a rather unexpected situation. Another one could be 'Damon's Bite', which focuses on the emotional turmoil that follows the bite. There are also many on platforms like Archive of Our Own that you can explore by using the relevant tags.
One great Damon and Jeremy fanfiction is 'The Bond Beyond Blood'. It delves into how Jeremy, after his experiences in Mystic Falls, starts to see Damon in a new light. Their relationship evolves from one of distrust to a sort of begrudging respect and then to an unexpected friendship. The story is full of action and the typical Vampire Diaries drama.
Well, in fanfiction, Klaus might kidnap Elena because he's lonely. He's been around for so long and has few people he can truly connect with. Elena represents something pure and good that he wants to possess. Also, he could be trying to use her as a pawn in his power games against other supernatural beings in Mystic Falls.
One common theme is redemption. Damon has a lot of past wrongs, and in many fanfictions, Bonnie plays a role in his journey towards redemption. For example, she might make him face the consequences of his actions in a more empathetic way.
Love. It's often a reason. Maybe he's being tortured because someone wants to get back at him for hurting their loved one. For example, if he broke a girl's heart who has a powerful father or brother, they might torture him to avenge her pain.
A theme that is often explored is the idea of sacrifice. In many fanfictions, either Damon or Caroline has to sacrifice something - it could be their own desires, safety, or relationships with other characters - for the sake of the other. This theme adds depth to their relationship and shows the extent of their love and loyalty towards each other.