The themes usually include the power of human emotions. Chiyuki's humanity and emotions start to affect Decim, so there's a lot about how emotions can change a being like Decim. Another theme is the idea of redemption. Decim might find a form of redemption through his relationship with Chiyuki, as he begins to understand the value of the souls he is judging in a different way.
Yes, there are quite a few. You can find some on fanfiction websites like Archive of Our Own. Some fanfictions explore their relationship further, showing how they grow closer and understand each other on a deeper level.
A 'chiyuki x decim kiss fanfic' could potentially be a great exploration of the characters' deeper emotions. Maybe the kiss is a turning point in their relationship. For example, it could be the moment when they finally admit their feelings for each other. If the original story has a lot of unspoken tension between them, this kiss in the fanfic could be a way to release that tension and start a new chapter in their relationship.
I think a good 'chiyuki x decim' fanfic would be one that delves deep into their characters. For example, a fanfic that explores how Decim's lack of emotions gradually changes because of Chiyuki. It could show their journey together, how Chiyuki's presence affects Decim's understanding of humanity. You can also look for fanfics recommended by other fans on social media groups dedicated to this fandom.
It could be a plot where Chiyuki and Decim are in a dangerous situation, and in a moment of desperation or relief after getting out of it, they share a kiss. For example, they might have just escaped from some powerful enemy in their fictional world.
Fanfiction.net might also have some 'chiyuki x decim' fanfics. It's an older platform but still has a wide range of works. However, the tagging system might not be as detailed as AO3, so you might need to do a bit more searching. You can also try Tumblr. Sometimes users post links to their favorite fanfics there, or even write short fanfics directly on their blogs.
One common theme is friendship. The relationships between the main character and the villagers or the animals are often explored in depth. For example, stories might focus on how the main character helps a sick animal and in the process, they become closer friends.
One common theme is the exploration of mortality. Given that death is a central part of the concept, fanfictions often look at how the characters in Harry Potter view death, deal with the threat of it, and what it means for their magical existence.
A frequently seen theme is mystery and intrigue. The Death Note itself is a source of mystery, and when combined with the reader being inserted into the story, there are more layers of mystery added. For example, how the reader's actions will affect the existing power dynamics between Light, L, and the other characters. Also, the theme of trust is common. The reader has to decide who to trust in a world full of deception, like whether to trust a Shinigami or a human character with their secrets.
One common theme is the exploration of their different personalities. Stein is this eccentric scientist and Death the Kid is this perfection - loving, orderly assassin. Their interactions can bring out themes of chaos versus order.
The theme of self - discovery within the relationship is also prevalent. As they interact more, both Kid and Liz learn more about themselves. For example, Kid might learn to be more flexible because of Liz, and Liz might become more responsible. This self - discovery not only affects their individual characters but also deepens their relationship in the fanfictions.