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.
I recommend the following pure battle energy novels, which list the levels of warriors according to Rest Gate, Life Gate, Pain Gate, Stop Gate, View Gate, Death Gate, Shock Gate, and Open Gate:
1. The main character, Xiao Yan, had walked all the way from the Dou Zhe to the Ruler stage, becoming the strongest Xiao Yan.
2. Life Gate-" Douluo's Nine-Tails Shocks the Heavens ". The main character was a reborn Douluo who had awakened the Nine-Tailed Sky Fox martial soul. Each tail was a talent, and each tail was a realm.
3. The main character, Shi Jun, had the most trashy wood-type fighting energy and the most trashy insect-type demonic spirit, but he relied on his tenacious spirit and strength to travel alone in the world.
4. Doomsday-" The Game: Breaking the Earth ". In the game world where humans only knew how to fight, the protagonist became one of the strongest existences because of his top-notch supernatural ability.
5. Jingmen-" Battle Break: I Can Upgrade All Things Unlimited ". The protagonist Feng Wu transmigrated to Battle Break the World and used experience points to upgrade all things to create the strongest strength.
6. Death Gate-" The Strongest Emperor ". The main character, Ao Lingtian, had the Emperor's Quality in Warrior Power. He was one of the strongest warriors in every corner of the Heaven Reverse Continent.
7. Startling Gate-< Talented Battle Master >. The main character Duan Lie had the talent of the four great grandmasters of secret medicine, forging, emblem, and appraisal. He also had the knowledge of battle energy and battle code, becoming the strongest god of war.
8. The main character, Xiao Fan, discovered the power of the nine heavens in the sealed planet space of the ancient soul race and dominated the Dou Qi continent.
In such fanfiction, the Kakashi OC often has unique physical features. For example, they might have distinct hair color or eye shape that sets them apart.
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.
There were novels similar to Sword Gates:
1."My Senior Brother is Obviously Very Strong, But He Likes to Grow." Author: Battle Saint Monkey
2:"Invincible Family with Cheat." Author: Que Yue
3. Yunhua Yao Ji, Author: Qi Zong
4. Spirit Origin Immortal, Author: Match Burning Match
The following is a detailed introduction of these novels:
1."My Senior Brother is obviously very strong, but he likes to develop": recommended
2."Invincible Cheat Family": Read this book when you're unhappy. It's very healing! It was funny. The author was definitely serious.
3.<<Yunhua Yao Ji>> I am a demon exorcist that is not very popular.
However, his ability was not weak. Just when I thought that I was going to spend my life calmly slaying demons. I lost my blade.
A demon slayer losing his blade is no different from losing his life, but I found another blade.
This saber had a human-shaped saber spirit.
The following is the story of how I brought the idiotic demon servant and the human-shaped saber spirit with facial paralysis (crossed out) around the world to eliminate demons.
Why did he have to exterminate demons? It was not a matter of national hatred. It was purely a matter of profession.
This book does not cultivate immortality.
4. Venerable Spirit Origin: Description: Mortal Stream-Online Intelligence-Invincible Spells, Qi Condensation-Foundation Establishment-Golden Core-Nascent Soul-Soul Formation, Spells-Beast Tamer-Talisman Creation
A young man from a rich mortal family had entered the cultivation sect, Water Cloud Stream, by chance. At the beginning of his cultivation, a mysterious drop of water appeared in his dantian…
Realizing that there was nothing in his heart, the little fish jumped out of the duckweed…
The reincarnated mighty figure, the natural sword immortal, the Golden Cicada Buddha, the nine generations of Demon Venerables, I have a hundred and eight thousand techniques…
You can read these novels on Qidian Chinese Network.
Kakashi could use his Sharingan to analyze Obito's moves and find a weakness in his defenses. Since he has the Sharingan, he might be able to predict Obito's attacks and counter them effectively, eventually finding an opportunity to break free.
Kakashi's reaction would be complex. He is a man who has lost many people in his life. But Naruto was special. He would hold Naruto tightly, his hands trembling slightly. He might try to use some of his own chakra to keep Naruto alive a little longer, but deep down he knows it's futile. His face would show a mixture of pain, regret, and love. He would remember all the times he trained Naruto, all the lessons he taught him, and how Naruto had surpassed all expectations.
Well, one similarity could be their determination. In the fanfic, like in the original series, both Naruto and Kakashi are very determined. Naruto is always striving to become Hokage and Kakashi has his own goals and missions he's dedicated to. They also might share similar combat styles in the fanfic, perhaps Naruto starts to adopt some of Kakashi's strategic thinking during battles.
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.