Lots of fans might write this type of fanfiction. Some might be amateur writers who just have a passion for the 'My Hero Academia' series where Todoroki is from. They could be using this as a way to express their thoughts on abuse and how it could play out in the context of the story. It's really hard to say exactly who writes it though, as it could be anyone from around the world who loves the character.
Well, it could be about Todoroki's abuse being brought to light. Maybe it focuses on how he copes with the revelations of the abuse, like his emotional journey. It could also explore how other characters in the fanfic react to the news of his abuse, whether they offer support or have their own biases.
His friends would probably take care of him. Midoriya would be very eager to help, using his kind-hearted nature. He would make sure Todoroki is fed and comfortable.
One common theme could be the exploration of emotional abuse that some characters might have faced but wasn't fully shown in the original series. For example, the neglect or mistreatment of certain students by some teachers. Another theme might be the psychological abuse that could have occurred within the Slytherin house, like the pressure put on students to uphold certain pure - blood ideals.
Fans of the character Carl usually write Carl fanfiction. They are often people who are really into the story that Carl is from and want to create their own versions of his story.
Fans of Onew write onew fanfiction. They are often people who are really into Onew as an artist, and they use their writing skills to create fictional stories about him.
There could be many different fans who write it. It might be an amateur writer who just loves Naruto and wanted to explore this unique scenario.
It could be written by amateur writers just starting out in the RWBY fanfic world who see commissions as a way to gain experience and make a bit of money or get some recognition. There might also be more experienced writers who do it for the fun of exploring different ideas within the RWBY universe that they might not have thought of on their own. And sometimes, a group of RWBY fans might collaborate on a commissioned fanfic, each bringing their own strengths to the writing process.
It could be written by fans who are really interested in the concept of 'old crow'. Maybe people who have a passion for the original source (if there is one) that the 'old crow' is related to.
Fans of Robert Pattinson and Kristen Stewart write robsten baby fanfiction. These are often fans who were really into their relationship on - and off - screen and like to imagine different scenarios involving a baby in their relationship.
There could be many different authors who write 'harry is trained fanfiction'. Fanfiction is a very open - ended and community - driven form of writing. It could be written by an amateur writer who is a huge fan of the original work (presumably something related to a character named Harry). They might write it just for fun or to explore a different side of the character that they feel wasn't explored enough in the original.