There could be fear as well. Fear of losing Luffy, especially if his injuries are severe. This fear might make her more cautious in the future, not wanting to put anyone else in danger because of her. At the same time, it could also fuel her determination to become stronger herself so that she can better protect those she cares about.
Vivi would likely feel a great deal of guilt. She might blame herself for putting Luffy in harm's way. After all, he got hurt because of her. This guilt could drive her to be more proactive in helping him recover.
There could be fear as well. Seeing Naruto injured, Sakura might be afraid of losing him. This fear could drive her actions in the fanfiction, whether it's in finding a cure for his injuries or in taking revenge on those who hurt him. It would also add more depth to their relationship as she grapples with these complex emotions.
In a plotline, the enemy might be after Vivi for some political reason. Luffy steps in without hesitation. He gets hurt but his determination to protect Vivi doesn't waver. This could lead to the Straw Hat crew coming together in a new way to face the threat. For example, Nami could use her navigation skills to find a safe haven where Luffy can recover while the others hold off the enemy.
Hotch would feel a great sense of responsibility. He's the leader, and Reid getting hurt might make him question his decisions that led to the situation. He'd be very protective and focused on getting Reid back to full health.
Twilight Sparkle would likely be extremely worried. Since she raised Spike, she would feel a deep sense of guilt, as if she failed to protect him. She might even blame herself for putting Spike in a situation where he could get hurt in the first place. She would probably rush to find a way to heal him, using all of her magic knowledge.
There would be a great deal of gratitude from Iris towards Shinra. She would likely feel guilty that he got hurt because of her. Shinra, on the other hand, might feel a sense of fulfillment in protecting her, despite the pain.
They would feel a mix of guilt and anger. Guilt because they might think they could have prevented his injury. Anger towards the person or situation that caused it. Eric would be especially emotional, as he and Ryan are close friends. They would all rally around Ryan, and this would strengthen their bond as a team.
The other characters would likely be very worried. Stella might be especially emotional as she's one of Flora's closest friends. She could be seen crying and constantly hovering around Flora, trying to make her feel better. Musa would probably be quiet but deeply affected, using her music to try and soothe Flora's pain in a way.
Yes, there might be such fanfictions out there. The world of fanfiction is vast, and with the popularity of the 'One Piece' characters Luffy and Vivi, it's possible that some fans have created stories around this concept. However, the quality and nature of these fanfictions can vary greatly. Some might focus on the relationship development that could lead to such a situation, while others might take more creative and unexpected turns.
In these types of fanfictions, Marinette's act of getting hurt protecting Chat can have multiple consequences. It could inspire other characters to be more heroic. It might also make the overall story darker and more complex. For instance, if Marinette is severely injured, the city may be in more danger as Ladybug is out of commission for a while. This then forces other characters to step up their game and fill in the gap. It can also lead to some really emotional and heart - wrenching scenes between Marinette and Chat, as they deal with the aftermath of her injury.
Yes, there are some out there. You can try searching on popular fanfiction websites like Archive of Our Own. Some writers might have created interesting stories where Luffy and Vivi get married, often exploring different aspects of their relationship and how it might change the One Piece world.