Grimm is the main character of the most games in the BLACKSOULS series. He’s who the player plays as, and canonically Grimm is an amalgamation of around 8 some of the most popular real-life authors who wrote fairy tales and similar literature.
For example, some of the authors inside Grimm are definitely: Lewis Carroll, the Brothers Grimm, Christian Hans Andersen, and the rest for now are left to speculation. That’s because those are the only ones mentioned by Mary Sue during the Ending C.
The reason why there are even so many authors merged into one person is also the doing of Mary Sue. Mabel describes Grimm as “Mary’s magnum opus” – magnum opus means the author’s greatest work.
In BLACKSOULS 2 you can experience flashbacks from Hotel Poseidon – this leads to a scene where souls inside Grimm argue with one another and basically have a mental breakdown.

