Fanfiction can be created by a wide range of people. Anyone with an imagination and a passion for a particular fictional universe can take a stab at it.
There could be many different authors who created fanfictions with this concept. It's hard to pinpoint just one. Fanfiction is a vast world, and often these unique ideas are created by individual fans who are inspired by the Sonic franchise and want to put their own spin on it.
I have no idea who created the 'cumming story' as there's not enough information provided. It could be an amateur writer, a local storyteller, or even a group of people.
The creators of 'The Boys' comic are Garth Ennis and Darick Robertson. They came up with the concept and brought it to life with their creative talents.
We don't have enough details to know the creator of 'caelzorah 100 fanfic'. It could be a person with a great deal of creativity who had an idea for this 'caelzorah' story and decided to write it. It might be someone who has been involved in the relevant fan community for a long time and wanted to contribute their own story, or it could be a new face in the fanfic - writing scene who just happened to come up with this concept.