Often, Gai is paired with Kakashi in Hurt Kakashi fanfiction. Gai, with his unwavering belief in friendship and his eternal rivalry with Kakashi, can be a great character to interact with a hurt Kakashi. He might try to pull Kakashi out of his slump through their friendly competition. Also, Rin is sometimes included. Since she has a significant past with Kakashi, her presence in the fanfiction can either be a source of comfort or more pain, depending on how the story is written.
Kakashi might be initially surprised. But then, he would probably use it as a teaching moment for Naruto. He could say something like 'Naruto, stealing is not the way of a ninja.' And then give him a punishment like extra training.
Often, Naruto is paired with Kakashi in such fanfictions. Their bond from the original series can be explored in new ways in the context of Kakashi's reincarnation. For example, Naruto might be the one to discover Kakashi's reincarnated form and help him adjust.
In this world, no one could succeed alone. Everyone had their own story, their own experiences, and their own way of learning. Everyone had their own life mentor, everyone had their own inspirational quote.
Just like a man who has been too light for countless years, but has a great ambition deep in his consciousness. He had been interested in all kinds of things since he was a child. When he was eight years old, he had already learned many languages and grammar. He was very interested in science and mathematics and had achieved some academic results.
From a young age, there was a spirit that decided not to give in. Even if he encountered setbacks, he would not stop. On the contrary, he would become more and more brave. He persisted in creating his own ideals and pursued his own ideals. Not only did he achieve academic results, but he also participated in many classic teams and brought his classmates a couple of years of age and success.
He was full of hope and longing for the future and believed that as long as he worked hard, he would be able to achieve his goal. He knew the importance of his perseverance, so he always kept learning and exploring and tried to be the best of himself.
Kakashi would likely be very concerned. He would immediately assess Naruto's injuries. If they were serious, he would use his medical skills to start treating him right away. His first reaction would be to make sure Naruto was stable and out of immediate danger.
Kakashi might immediately offer a comforting presence. He could put his hand on Naruto's shoulder and just be there silently, letting Naruto know he's not alone.
Kakashi may also get angry. Angry at the people or things that caused Naruto to get those scars. This anger could fuel his determination to make Naruto stronger, so that he can better defend himself in the future. He might then intensify Naruto's training, all while having a new - found sense of protectiveness towards Naruto.
One possible motive could be to help Naruto control the Nine - Tails' chakra better. Hypnosis might be a way to reach into Naruto's subconscious and find a way to coexist with the powerful force inside him.
Naruto would probably be one of the first to try and rescue Kakashi. He has a strong bond with Kakashi and would not stand by while his teacher is in danger.