One way the plot could go is that Merlin's friends start to suspect something is wrong. They notice his strange behavior, like wincing when he moves too quickly. This could lead to a series of events where they try to figure out what's wrong with him, and Merlin has to keep coming up with excuses to avoid revealing his broken ribs.
The plot could develop with Merlin gradually getting worse. His broken ribs might prevent him from using his magic effectively. For example, when he tries to cast a spell, the pain from his ribs could cause him to lose focus and the spell could go awry.
The plot might develop as Merlin's broken ribs put him in danger. Maybe there's an enemy who senses his weakness and tries to take advantage of it. Merlin then has to use his wits and whatever remaining strength he has to outsmart the enemy, all while dealing with the pain of his broken ribs. It could be a story of his struggle and ultimate triumph over his physical and external challenges.
Well, it could be a story about Merlin trying to hide his broken ribs while still performing his duties. Maybe he's worried that if Arthur finds out, he'll be restricted from doing certain tasks.
Percy might become more empathetic. Since he's usually the strong one, being injured would make him understand what it's like for others who are hurt. He could develop more patience as he has to wait for his ribs to heal.
Maybe Percy breaks his ribs in a training accident at Camp Half - Blood. This could lead to him feeling frustrated as he can't participate fully in activities. He could then discover a new way to train or gain power while recovering, perhaps by learning more about his demigod heritage in a different way.
He might become more confident in his magic. Among the druids, his magic would be accepted and even celebrated. So he could practice more freely and learn new spells and techniques, which would boost his self - assurance. Also, he could develop a stronger sense of community as the druids live in a more close - knit way compared to the hierarchical structure of Camelot.
The plot could start with Naruto suddenly getting a high fever. His friends notice his strange behavior like being more sluggish than usual. Then, they take him to the hospital. As he's recovering, he could start to remember some forgotten memories related to his parents or some past traumas.
At first, their relationship might be one of master - servant formality. Shirou would be cautious and respectful, while Merlin would be somewhat aloof. But as time goes on, Shirou's determination and pure heart could win Merlin over. Merlin might start to see Shirou as more than just a master, but as a friend or someone worthy of his real help.
You could have him rest and recover gradually with the help of his friends and dragons.
Their relationship might start with distrust. Harry, like Arthur, may be wary of Draco, as Merlin, due to their past differences. But as they face common enemies, they begin to rely on each other. Draco's magic skills, similar to Merlin's, prove useful to Harry, and they gradually form a bond of friendship and mutual respect.
You could also develop the plot by focusing on the physical and emotional changes Merlin goes through during the pregnancy. He might struggle with the hormonal changes, just like any pregnant person would. Emotionally, he could become more protective of Gwen and the unborn baby. Meanwhile, they might have to deal with threats from outside forces who somehow find out about the pregnancy and want to use it for their own gain. This could add a lot of action and suspense to the fanfiction.
The term 'merlin broken fanfiction' is rather open - ended. It could be that the fanfiction explores a 'broken' Merlin, perhaps one who has lost his faith, his powers, or his sense of purpose. For example, the story could be set after a great tragedy in Camelot where Merlin feels completely broken and the fanfiction delves into his journey to heal or find a new path.