Typically, his novels have a strong sense of mystery. For example, in 'The Decagon House Murders', there are multiple layers of mystery, from the identity of the murderer to the secrets hidden within the decagon house.
One of his notable novels is 'The Decagon House Murders'. It has a really interesting mystery setup with a group of students visiting an isolated island with a decagon - shaped house. The story unfolds with various murders taking place, and the way the mystery is gradually solved is quite engaging.
Most BSD light novels often have complex characters. Since they are based on literary figures, they bring in the depth and complexity of those original personas. For example, a character might have the same traits as a famous writer but with a unique twist for the BSD universe.
Well, I'm not entirely sure about all of them, but some works in Ayatsuji Tsukasa's visual novels are known for their complex mystery elements. They often keep the readers on their toes with unexpected plot twists.
A fanfiction could focus on the everyday adventures of Touya and Yukito. For example, they could go on a simple trip together. During this trip, they might encounter some minor magical occurrences that are not directly related to Sakura's card -capturing. It could be a story about their friendship growing stronger through shared experiences and how they support each other in different situations.
Well, in Touya and Yukito fanfiction, a frequent theme is the exploration of their emotions. Since they have a complex relationship, fanfic writers often focus on how they feel about each other. Additionally, the theme of loyalty is common. Their loyalty to each other in different situations is often depicted in these stories. And sometimes, there are fanfictions that touch on the theme of sacrifice, where one might sacrifice for the other's well - being.