i got my sister sort of into BSD, and she thought of an idea for Arthur Conan Doyle. Also apparently Harry Houdini is an author(like he has several books). Also those two were friends apparently and Arthur was convinced Harry was actually magic, Harry was apparently not amused and tried to convince him otherwise. This is important information.
Basically her idea was, Harry's ability was similar to Dazai's but with a larger range, and Arthurs was basically just what Ranpo thinks he has.
Also that Arthur doesn't believe abilities exist. Like, he has one, he just doesn't believe that it's an ability. Harry does nothing to persuade him otherwise. She thought of this because I told her Asagiri liked to switch around dynamics sometimes.
Personally, I want Arthur to have trauma related to his ability if he was like Sherlock. Because he hated Sherlock Holmes. He thought his poems were better. On the other hand, it would be funny to have him be all like 'my ability is better than everyone else's'. Anygays, can't wait for him to be officially introduced in BSD. Hopefully he is 💀