Yes, I know some Angel Beats Doujin novels. Angel Beats was a very popular Japanese light novel. The storyline was different from the original, and there were often various re-creations.
Some of Angel Beats 'doujinshi novels may include different characters, reconstructed plots and worldviews, as well as different storylines such as love, adventure, fantasy, etc. These novels were usually written by different authors and used different styles and styles.
Some of the famous doujinshi novels include Angel Beats in Heaven and Angel Beats! "Angel Beats of the Lost Souls" and so on. These novels had a wide readership and were often regarded as derivative works of the original work because they usually had higher storylines and character descriptions.
One interesting Angel Beats OC fanfiction could be about an OC who has a special musical ability that changes the way battles in the afterlife are fought. For example, their music can soothe the souls of the enemies, making them question their reasons for fighting.
You might be able to find it on some dedicated gaming platforms or online stores that sell visual novels. Try looking on Steam or popular digital game marketplaces.
There are definitely some out there. In some fanfictions, they might start off as just comrades in the fight against the system in Angel Beats. But as the story progresses, their bond deepens. Maybe they share a moment of self - discovery together, realizing things about themselves through their interactions with each other. It's really fascinating to see how different authors interpret their relationship in the context of the Angel Beats world.