One main theme is often self - discovery. Asriel discovers his sexual orientation and learns to accept himself. Another theme can be love against all odds, where his relationship faces challenges but still prevails.
Friendship is a very common theme. Since Chara and Asriel are so close in the original story, many fanfics explore the depth of their friendship, how they support each other and grow together.
I'm not very familiar with 'asriel butt fanfic' specifically, but in general, fanfic can have themes like friendship, adventure, or self - discovery. Maybe in this type of fanfic, there could be themes related to the character's growth or relationships within the story's context.
To write an Asriel gay fanfic, start with research. Know the lore and the world where Asriel exists. Next, focus on character building. Make his gay identity a natural part of who he is. For example, you could write about how he discovers his feelings. Develop a plot that is engaging, like a forbidden love scenario if it fits the universe he's in. Also, use vivid descriptions to bring the story to life.
One common theme could be family. Given their relationship, stories might focus on the family dynamic between them.
One common theme could be power dynamics. Since Asriel is in a dominating position, it often explores how power is exerted and how Frisk reacts to it. Another theme might be character growth. Frisk could potentially grow in the face of this domination, either by learning to resist or by finding a new way to interact with Asriel.
Another theme is redemption. Asgore might have made some mistakes in the original story, and in these fanfics, Asriel can play a role in his redemption process. It shows how love and family can be a driving force for change. For example, in some fanfics, Asriel helps Asgore come to terms with his past actions and move towards a better future. This often involves a lot of emotional conversations and growth for both characters.
Well, I know 'Shades of Love' which is a great 'Asriel x Chara gay fanfic'. It starts with their childhood memories and gradually unfolds their evolving feelings for each other. There are also some fanfics on websites like Archive of Our Own that you can search for under the relevant tags.
One popular 'gay Asriel fanfic' could be 'Asriel's New Chapter'. It explores his character in a different light with a gay relationship aspect. Another might be 'Asriel's Hidden Love' which delves into his emotions and a secret gay relationship he might have.
One common theme is redemption. Since Asriel has a complex past in Undertale, many fanfics use the relationship with Sans to explore his path to redemption. Another is friendship. Despite their differences, they can form a unique bond.
Common themes include loyalty. Chara and Asriel had a strong bond, and fanfics often showcase how loyal they are to each other, even in difficult situations. Another is the theme of discovery. They discover new things about themselves and each other through their interactions in the fanfics. Also, the theme of hope can be seen. In a world that can be dark like undertale, their relationship can be a source of hope, and fanfics play with this idea, showing how they bring light to each other's lives.