This is probably the most unexpected couple that has a good potential for a relationship. I warn you, there's a lot to say. I may sound crazy, but I have reasons to believe that these two could at least be good friends. To begin with, they are opposites, and as we know, opposites attract. Jonah is an example of an aristocrat who is bound by certain rules, while Fenrir embraces a free-spirited lifestyle. Jonah is a perfectionist so he prefers perfect order, Fenrir on the other hand is not picky, I would even say he is the complete opposite of the word order. Jonah is very strict with himself, Fenrir often doesn't even think about judging himself for literally everything. Jonah doesn't have control over his own life because his fate was predetermined before he was even born, and at the moment, his future is still being decided for him by his father, while Fenrir, on the other hand, is taking control of his own life, building the future he wants, and living life to the fullest.
Unfortunately, Jonah's position doesn't allow him to truly enjoy life. Therefore, someone like Fenrir could help him become more simple and ordinary. With Fenrir by his side, Jonah could stop pretending to be perfect and enjoy the simple things in life like a regular person. I know this theme is primarily explored in the Lancelot's route, but I believe that Jonah himself desires to live like a regular person deep down, but his responsibility as the Queen of Hearts prevents him from doing so. Therefore, I believe that Fenrir is the person who could teach Jonah to be a human being, rather than an emotionless puppet in the face of others. He could teach him to be honest with his feelings.
Fenrir is a man who has chosen his own path, despite being from a famous and wealthy family. Such a distinction would help him give Jonah the confidence he lacks.
The next point is that Jonah has an inferiority complex and doesn't really like himself, but Fenrir, with his character, could help Jonah to love himself for who he really is. For example, by constantly complimenting Jonah in a way that our Queen would be embarrassed by. There's another example where Fenrir, once he knows who Jonah really is, could always find joy in Jonah's flaws and see them as perfect complements. And knowing Fenrir's character, he's too good to praise someone for their flaws instead of their perfect image. This is exactly what Jonah needs, so he can gradually learn to love himself and stop being afraid, at least in front of Fenrir, to make mistakes and most importantly, to be himself.
There's another interesting point. Between the Red and the Black Army, there are a couple of close friends who complement each other. For example, Edgar and Luka, Lancelot and Sirius, and so on. Jonah and Fenrir could be an interesting and chaotic couple of friends with a unique dynamic. It's sad that Jonah doesn't have any close friends (Lancelot doesn't count) who he can be himself with and not be afraid to open up to. I know he's friends with a lot of people, but he doesn't have any alternatives when it comes to a true friend. After all, Lancelot is his king, and he has authority in the army. I don't think Jonah would dare to come to him and tell him that he's in trouble and needs help. He's used to solving problems on his own, as his parents never helped him with his issues. So, I don't think he would bring his problems to Lancelot. If Fenrir became his close friend, there's a chance that Jonah would open up to him. It's also interesting to know that Fenrir would definitely do his best to help Jonah with any problem, even if the problem was Jonah himself, for example, if he made a mistake. This is because Fenrir is a very kind and supportive person who would never bully or be rude to someone in need.
I think they would have had a fun dynamic as friends, given Fenrir's tendency to deliberately annoy Jonah just to see his adorable reactions. While they wouldn't have engaged in physical altercations like Fenrir's interactions with Ray, but Jonah would have responded to Fenrir's playful banter. It's also cute to imagine how Jonah has a weakness for the kind of guys you can't really be angry at for long, considering how much they're like cinnamon rolls. Despite his ostentatious arrogance, Jonah wouldn't really hold a grudge against Fenrir.
I would like to now talk about how it's not just Jonah who needs Fenrir, but the idea also works in the opposite direction. Fenrir also needs Jonah. First of all, Jonah can finally help Fenrir overcome his guilt from the incident in the past and finally leave it behind. Jonah is very sensitive to others and understands the feelings of others, so he could notice that Fenrir has problems that are bothering him and try to help. Jonah could teach Fenrir to accept support from others by talking to him about his experiences. After all, Jonah is older than Fenrir, so he can give him advice, especially since he often feels guilty himself and deals with it differently. Jonah could also teach Fenrir to be more composed and serious at the right time. I don't mean that Fenrir isn't serious, but it would be interesting to see if Jonah's sense of responsibility for others is passed on to Fenrir, as it would contribute to his character development. This would allow him to make difficult decisions without hesitation. It might even help him to fully let go of his guilt over past incident.
One of the important reasons why Fenrir needs Jonah is that Jonah would take better care of Fenrir than our beloved Ace of Spades does. To be honest, Jonah always takes care of others like the group's mother. His care for others is often overlooked, and Sirius is constantly mentioned in this role, even though Jonah is just as good as Sirius and has the same mom energy. I'm saying that because Fenrir always thinks about others first, not about himself. He doesn't know how to accept support and care for himself. This means that Jonah can teach him to take care of himself sometimes, rather than others. I always felt that Fenrir is constantly solving the problems of others, while not trying to deal with his own problems (he has problems, but they are not as dire as those of other guys). Therefore, someone like Jonah, who is good at taking care of others, will take care of Fenrir since he is not doing it himself. On the other hand, Fenrir will take care of Jonah, which shows that they complement each other. They will literally take care of each other more than they take care of themselves, and together they will be able to solve their problems.
Another example is that Jonah can be Fenrir's voice of reason and his brain in certain situations. To be honest, Jonah seems like the kind of person who would stop Fenrir from acting impulsively before thinking things through. It's funny because they're both impulsive and emotional, but compared to Fenrir, Jonah seems to think things through before acting. Additionally, I think it would be cute if Jonah became less of a bore thanks to Fenrir, and the two of them would get into some silly stuff. To imagine that Jonah, the Queen of Hearts, who is always for the law, would end up breaking a rule is incredibly adorable to me. He probably wouldn't do that with other people (except maybe MC in some cases). However, Fenrir's philosophy would have made him free from the constraints of eternal rules, allowing him to understand that breaking them in certain situations is not necessarily a bad thing.
It's sad that there's no interaction between them as friends, but they could at least be good partners who perfectly represents the ideologies of their armies and have proven how they can work together to save their homeland despite their differences. Jonah perfectly represents the ideology of the Red Army, despite his strict family life, while Fenrir, with his free-spirited lifestyle, perfectly represents the ideology of the Black Army. I believe Fenrir does this better than Ray, but that's just my opinion. Considering everything I said earlier, I think they are a very good example of different yet similar people who are learning to work together. In this context, they would be like the sun and the moon. Fenrir is the sun, and Jonah is the moon. Cute fact: the moon reflects the sun's glow, which could be a parallel to how Jonah's smile became innocent and happy thanks to Fenrir, that's because Fenrir is the source of his happiness.
In the end, they are a good trope of characters who are both opposites and yet complement each other so well. With their relationship, you can come up with a lot of drama and plot, such as them being alone against everyone even before the truce between their armies, because they could literally turn everyone into their enemies for the sake of each other. This plot is possible because Jonah had a similar situation in his route but in a simpler way. Additionally, if they were in a relationship, their marriage could unite their armies and resolve their differences once and for all, as their bond would be real and voluntary rather than marriage of convenience. This list can go on and on, and if I delve deeper into these thoughts, it will go on even longer. If I don't stop myself, I'll be carried away by my ideas, as I love them dearly at least as friends, and I can't even imagine the obstacles they might face in their relationship. After all, you believe in romance when the characters go through many trials that test their relationship.
P.s. besides, since we have friendship and relationships between the kings, why don't we have anything between their close friends? Although they were the first four to show us their world and their hearts could be won. Therefore, I believe it is a big oversight not to reveal their relationships. Unfortunately, the game is no longer being updated, so there won't be any official content related to them. However, we can create our own content with them. Although it's likely that only I will create minimal content about them, as it's unlikely that anyone would seriously share these feelings with me. And lastly, I came to the game after they stopped updating it, so if these two had any interactions in events, it would be interesting to know.
Their relationship is like Hinata and Kageyama's relationship from Haikyuu, how unsee that. A little more precisely, their dynamics are Natsu and Elsa, what's wrong with me?