Sanji would go all out in cooking the most nutritious and delicious meals for Usopp to help him recover. He might also be a bit overprotective, not allowing anyone to disturb Usopp while he's eating. Chopper would be in full - on doctor mode. He'd be constantly checking Usopp's vital signs, giving him medicine, and trying to figure out the cause of the sickness. Robin would be quietly researching any possible cures or causes, using her knowledge of history and ancient texts.
The crew as a whole would rally around Usopp. Brook might play some soft music to soothe Usopp. Franky could use some of his inventions to make Usopp more comfortable, like creating a special bed or a device to regulate the temperature in the room. They would all be worried about Usopp, but at the same time, their unity and different skills would come into play to take care of him and get him back on his feet as soon as possible.
The characters' reactions can be quite diverse. Chopper would be extremely worried and immediately start his medical examination. He'd be constantly checking Luffy's symptoms and trying different remedies. Nami would be worried too but also thinking about how this could affect their journey and the crew's safety. Zoro might seem nonchalant on the outside but would be secretly on high alert, ready to fight off any danger. Sanji would cook up all kinds of nutritious food to help Luffy get better.
In a fanfiction, Usopp could get sick from a cursed item they found on an ancient ruin. This sickness slowly drains his energy and his ability to tell lies (which is a big part of his character). Luffy, not fully understanding the severity, tries to cheer Usopp up in his own goofy way. Zoro might be more practical and keep a lookout for any enemies who might take advantage of Usopp's weakened state. Chopper, of course, is desperately trying to find a cure, but is facing difficulties due to the unknown nature of the curse.
In the past, Usopp's abilities like his slingshot skills might be seen as more primitive compared to the advanced weaponry in his own time. But his creativity could give him an edge. For example, in a time when there were less advanced long - range weapons, his slingshot could be a very unique and effective tool. In the future, if he travels there, his abilities might seem obsolete at first. However, he could adapt by using his knowledge of old - fashioned combat and combine it with the new technology he finds.
His friends would most likely be very concerned. They would probably bring him things like food and medicine. TK might pray for his quick recovery.
Olaf would try to make Anna laugh. He would tell his silly jokes and do his goofy dances. He would also try to keep Anna warm with his carrot nose. He might even build a small snowman inside the room to keep Anna company when everyone else is busy.
Nya would be very worried. She'd probably stay by Jay's side as much as possible, trying to take care of him and find a way to make him better.
The Straw Hat crew would have a mix of reactions. Franky might start building a special nursery on the ship, using all his engineering skills to make it safe and comfortable. Robin would be a source of calm and knowledge, sharing stories about pregnancies in different cultures she's read about. Brook would be playing gentle music to soothe Nami. And Luffy, as the father, would be constantly by Nami's side, sharing his positive energy and telling the baby stories about their adventures, even though the baby can't hear them yet. Overall, the crew would come together to support Nami and the new life coming into their world.
His other friends like Shikamaru would think of the most practical solutions. He might calculate the risks of continuing the mission with a sick Naruto and come up with a plan. Maybe he'd suggest splitting the group, with some staying to take care of Naruto and others proceeding with the mission - related tasks that can't be postponed.
Lissa would immediately spring into action. As a healer, she would be examining Robin, trying different spells and potions to make them better. She would be constantly by Robin's side, fussing over them and making sure they were taking proper rest.
Raven would probably be the first to sense that something was wrong with Beast Boy. She'd be quiet about it at first, but she'd start keeping a closer eye on him. Maybe she'd make him some herbal tea that she believes has healing properties.