I really like 'The Unspoken Connection'. In this fanfic, the chemistry between Kanda and Allen is palpable. It starts with a simple mission they go on together and gradually builds up their relationship in a very believable way. It's a great read for fans of the pairing.
The gray man is often described as having a hazy or shadowy appearance, like a figure made of mist. He is usually associated with a feeling of coldness.
First, understand the characters. Know Grant and Nate's personalities, their likes and dislikes. For example, if Grant is shy and Nate is outgoing, you can use these traits to create interesting interactions. Second, come up with a unique plot. It could be something like they team up to solve a school mystery. Third, use vivid descriptions. Describe their surroundings, like the dusty attic where they search for clues, and their emotions, such as Grant's nervousness when facing a challenge.
First, study the characters from the D.Gray - Man series. Understand the nature of the Noah and the significance of the Mother figure. Then, come up with a unique plot. For example, you could set it in an alternate universe where their relationship is different from the canon.
One idea could be exploring the origin of their relationship. Maybe the Noah has a unique connection to the Mother figure that predates the events of the main story. This could involve flashbacks and revelations about their past interactions.
One great place to find Kanda x Allen yaoi fanfiction could be Archive of Our Own (AO3). It has a large collection of fan - created works for D Gray - Man. Just search for the tags related to Kanda, Allen, and yaoi.
One common theme is the exploration of their complex relationship. Given their different allegiances in the original story, fanfictions often delve into how they might interact outside of the main plot's conflicts.
A recurring theme is the power dynamics. The Noahs are powerful entities in the D Gray - Man universe. So, how the reader, who is usually a normal human or has some special ability, copes with the power of the Noahs is often explored. It could be about the reader fearing the power, trying to gain power equal to the Noahs, or using the Noahs' power for their own good. There is also the theme of acceptance. Whether the reader accepts the Noahs for who they are or tries to change them is something that many fanfictions focus on.
One common theme is the exploration of Kanda's cold exterior. Fanfics often try to break through that coldness with the reader's character. For example, in many stories, the reader is the one who starts to make Kanda show his softer side.