One great fanfic idea could be a story where Yor and Loid have to go on a mission together outside of their normal family cover. Maybe they end up in a foreign city and have to rely on each other more than ever. This would deepen their relationship and also add some exciting action and adventure elements to the story.
Well, a simple fanfic could just be about Yor and Loid sharing a quiet moment at home. Just them talking about their day, and slowly realizing how much they've come to rely on each other. It's a sweet and simple concept that shows the growth of their relationship.
If RWBY were to react to Spy x Family fanfiction, they would bring their own perspectives. Ruby, with her innocent and curious nature, would likely be intrigued by Anya's telepathic abilities. Weiss, being more refined, might analyze the political and social aspects of the Spy x Family world. Blake, having experienced secrecy herself, would empathize with the characters hiding their true identities. Yang would enjoy the comical moments and the action - packed sequences, like when Loid does his spy stunts.
Spy x Family manga has wrapped up. It provided a conclusive and fulfilling storyline that wrapped up all the loose ends. Now you can binge-read the entire series without any interruptions.