His butler, Kuroba Toichi, if still alive in the fanfiction world, would surely come to his aid. He has a lot of experience and resources, and his loyalty to Kaito Kid would make him a natural choice to help him when he's hurt, whether it's by providing medical assistance or getting him out of a dangerous situation.
Hermione would definitely be one of the first to help. She's extremely intelligent and well - read in magic, so she'd quickly start looking for spells or potions to heal Harry. She'd also stay by his side to comfort him and keep his spirits up.
Nobara Kugisaki and Megumi Fushiguro could also be among those who help. Nobara is a strong - willed and capable sorceress. She would be concerned about Nanami's well - being and use her skills to assist him. Megumi, being a calm and intelligent sorcerer, would likely come up with a plan to rescue or heal Nanami. They all share a sense of comradeship within the Jujutsu Kaisen world.
Dr. Bruce Banner could play an important role. His scientific knowledge could be used to analyze Captain America's condition and come up with solutions. In some fanfictions, he might even find a way to enhance Captain America's healing abilities. Also, Thor, if he's around, could use his Asgardian magic or knowledge to help in the healing process, perhaps by bringing some rare Asgardian herb or elixir that has healing properties.
In some fanfictions, Kaito Kid could get hurt due to unforeseen circumstances like bad weather during a rooftop escape. He might slip and fall, resulting in an injury. This type of plot can lead to a different side of his character being explored, as he has to deal with being injured while still trying to maintain his secret identity and evade capture.
Lisbon would probably be the first one to help. She has a deep connection with Jane and cares about his well - being.
One likely character would be her closest friend. This person would be by her side immediately, providing emotional support and maybe even some basic first - aid if they are able. They would stay with her throughout her recovery process, being a source of comfort.
Katara would be a likely character to help Toph recover. Katara is a waterbender and has healing abilities. She would use her skills to tend to Toph's injuries, whether they are physical wounds or internal damage from overusing her earthbending. Another one could be Aang. He's the Avatar and has a deep connection with all the elements. He might use his spiritual knowledge to help Toph heal faster, maybe by finding a special place for her to rest and regain her strength.
Tails is very likely to help. He's Sonic's best friend and is super smart when it comes to technology. He could build a device to speed up Sonic's recovery or find a way to treat Sonic's injury. Amy is also a possibility. She's very caring and would do anything to make Sonic feel better. And Knuckles might help too. He's strong and could protect Sonic while he's recovering.
In some fanfictions, Jane Foster could play a role. If she's around Asgard at the time, being a scientist, she might have some knowledge or technology that could be used to treat Loki's wounds. Also, Valkyrie could be a helper. She's a fierce warrior and has a sense of honor. She might see Loki's injury as a chance to prove her worth or as a debt she needs to repay if Loki had previously helped her in some way. And of course, Frigga, if she were still alive in the fanfiction, would be a great source of comfort and healing magic for Loki.
Sherlock Holmes is a great choice. His deductive skills would contrast well with Kaito Kid's thieving skills. Another good one is Lupin III. They are both master thieves, and a crossover between them could be full of interesting heist scenarios. Conan Edogawa would also be interesting. Since he's always trying to catch Kaito Kid in the original series, a crossover could explore new dynamics between them.