In the light novel, Ayanokoji is clearly the more intelligent one. He has a unique ability to analyze situations and people's motives deeply. Ryuen often falls into Ayanokoji's traps because he doesn't fully understand Ayanokoji's true nature. Ayanokoji can anticipate Ryuen's moves and counter them effectively, while Ryuen struggles to keep up with Ayanokoji's complex thinking.
I'm not sure specifically which light novel this refers to. There could be many different interpretations and works with such a concept. It might be a relatively unknown or very niche light novel character.
One Piece: The Demonic Epic and One Piece: Unlimited Stamina are both novels where the main character is an ability user and has a strength of D. I can recommend them to you. I hope you like this fairy's recommendation. Muah ~😗
Again, without knowing the specific light novel, it's impossible to say for sure. But generally, he might be wise, as he could be in a position to guide class d adventurers.
I don't know for sure. The ending of such a manga can be quite unpredictable and might not have been revealed yet. You could try discussing it with other fans to get their speculations.
The development can also be based on personal growth. Horikita is often very focused on her own goals and can be a bit cold. Ayanokoji could be the one to help her see the importance of relationships. Maybe he shows her how a more empathetic approach can help in achieving their class's success. This would lead to Horikita opening up to him more, and Ayanokoji in turn would start to show more of his true self to her. Over time, a deeper relationship could form as they both grow as individuals within the context of the fanfic.