Communication is key. They can start by sharing their fears and hopes. For instance, Gregory can talk about his loneliness before coming to this place, and Vanessa can share her own struggles with her job. This mutual understanding will bring them closer.
I really like 'Gregory and Evan's Adventure'. In this fanfic, Gregory and Evan embark on a journey together. It has a lot of action and adventure elements. Their friendship is tested along the way, but they always manage to come out stronger. It's full of exciting twists and turns that keep you hooked from start to finish.
Some fandom - specific forums might also have Gregory x Evan fanfic. You can join these forums and ask the members if they know of any good stories. They might even have some exclusive fanfics that are not available on the larger platforms.
One idea could be that Vanessa and Gregory are on a mission to uncover the secrets of the old parts of the building they're in. They face various challenges together and their bond grows as they rely on each other's skills. For example, Gregory's quick thinking and Vanessa's knowledge of the place help them avoid the security mechanisms.
The plot might be a key factor in making it unique. If it has an original and engaging story, perhaps with unexpected twists and turns, that would make it stand out among other light novels. Also, the writing style could be something that gives it a special charm, whether it's very descriptive or has a unique narrative voice.
I'm not very familiar with 'lilliane la christophe' light novels specifically. However, you could try searching for it on specialized light novel websites or forums. They might have user reviews and recommendations that could help you find some great ones.