On the other hand, he could become more empathetic. Having suffered such a traumatic injury, he might understand the pain of others better. This could lead to him being more lenient with his subjects, more willing to help those in need, and more involved in the well - being of his kingdom. His experience with the dragon fire could be a turning point in his character development towards a more compassionate leader.
He might become more cautious. After experiencing the pain of the dragon fire, he could be more hesitant in engaging in battles, especially those involving dragons. This could change his military strategies.
It could be that there was some sort of magic involved. Maybe an enemy of Thranduil cast a spell that made the dragon more aggressive towards him. The dragon fire might have some special properties due to this magic, and Thranduil's burns could be not just physical but also have some sort of curse or negative effect on his being. He then has to find a way to break the curse while dealing with his injuries.
Katniss could develop a stronger sense of self - reliance. After going through such an ordeal, she might not trust others as easily to protect her. She'd rely more on her own skills and instincts. For instance, she might take more risks in her attempts to take down the Capitol because she feels that she has already endured the worst that the Capitol can do to her. Also, her relationships with her family and friends would likely change. She might be more protective of them, but at the same time, she could be more withdrawn as she doesn't want to put them in danger because of her own situation.
😋It's a novel about urban entertainment stars, but it might not be completely in line with the "dark novel" type that you described, but the main character did obtain animal abilities after being injected with a drug. I hope you like this fairy's recommendation. Muah ~😗
Another place to look is Archive of Our Own (AO3). There are a lot of talented writers in the Tolkien fandom there. A good fanfiction might involve Thranduil having to protect his people from a dragon's fire. Maybe the dragon has been awakened by some dark magic and Thranduil is the only one who can stop it. The fanfiction could explore his character development as he overcomes this great threat.
His character might become more confident. Finding a dragon gives him a powerful asset, so he would likely stand taller and be more assertive.
Naruto's character could develop in a way that he becomes more of an outcast hero. He might start to fight for the rights of those who are wrongly banished or persecuted. His experience of being banished gives him a unique view on the world, and he uses this to challenge the norms of the ninja world when he returns or while he is away, depending on the plot of the fanfiction.
Naruto may also gain a deeper understanding of Kakashi's own struggles. As he recovers from the hurt, he could start to realize that Kakashi might have had his reasons, whether it was to protect Naruto in a strange way or because of Kakashi's own internal conflicts. This new understanding could lead to a more complex and mature relationship between them.
He might become more independent. Without the support of his usual allies, he has to rely on himself. So he could learn new skills like hunting for food in the wild or building shelters. This would make him a more self - sufficient character.
She could develop a more independent streak. Before, she was often following Roman's lead. Now, she has to make her own decisions. This could lead to her making mistakes at first, but over time, she might grow into a more confident and self - reliant character. For instance, she may start to develop her own fighting style rather than relying on Roman's strategies.
You could have other characters come to his rescue and help him recover.