A theme that frequently shows up is redemption. Klaus, being a complex and often villainous character, may be on a path to redemption in some fanfictions, with Stefan either helping or hindering. Also, power dynamics play a role. Klaus is very powerful, and Stefan has his own set of abilities, so how they interact in terms of power is a common theme. For example, in some stories, Stefan has to find ways to level the playing field when dealing with Klaus.
You can find 'Stefan and Klaus fanfiction' on popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of fan - created stories with various themes and ratings related to different fandoms, including this one. Fanfiction.net is also a good place to look. It has been around for a long time and has a wide range of stories.
One great 'Stefan and Klaus fanfiction' is 'The Bond Beyond Enmity'. It delves into how their complex relationship could develop in unexpected ways, like finding common ground in protecting Mystic Falls from a new threat. Another is 'A Different Alliance' which explores a scenario where they team up for a personal vendetta against a more powerful enemy.
He could be very protective. Klaus has always seen Caroline as someone special. Now that Stefan is gone, he might feel a stronger urge to keep her safe. He may try to show her that he can be a better option for her than Stefan ever was, not in a mean way, but out of his own feelings for her. He'll likely be very gentle at first, trying not to spook her.
There's a fanfiction called 'Shared Secrets'. In this story, Klaus and Stefan find themselves in a situation where they have to share their deepest secrets to survive. It's really interesting as it shows a more vulnerable side of both characters. And 'The Unlikely Alliance' is also good. It starts with a small encounter that gradually leads to a big adventure where they rely on each other.
Well, Caroline might be filled with a mix of emotions. She could be angry at Klaus for past wrongs, yet also find some comfort in his presence. Maybe she'll finally let out all the pent - up feelings she had for Stefan in front of Klaus. It could also lead to a new chapter in their relationship, where they start to see each other in a different light, perhaps even becoming friends or more.
In the TV show, Stefan is played by a particular actor, which gives a visual representation. In the novel, readers might have a different mental image of him. Also, the TV show might have added some plotlines for dramatic effect that are not in the novel. For example, some relationships might be developed differently in the two versions.
In the comics, Klaus is not immortal. He may have certain powers and abilities, but there are limitations and factors that can pose a threat to his existence.