Maybe it has the ability to absorb chakra. So when Naruto is in a fight against an opponent with a large amount of chakra, he can use the sword to drain some of that chakra, weakening the enemy while strengthening himself. The sword could then store that chakra for later use, like to boost Naruto's own attacks.
It could be a sword that can cut through any substance, like the Susanoo easily. Just imagine Naruto swinging it and slicing through powerful jutsu defenses as if they were paper.
Well, it really depends on the specific fanfiction. Some fanfictions do make Ichigo overpowered. They might do this to explore different storylines or just for the fun of it. For example, in some, he could have a sudden boost in his reiatsu that makes him almost unbeatable. But not all fanfictions take this route. There are also those that focus on his character development in a more realistic way within the context of the Bleach universe and don't make him overly powerful.
There were novels similar to "
1:"People Encounter Snow on the Road", Author: So Ci Nian
2." My Game of Becoming a God in Another World." Author: Crush
3. Dark Card God, Author: Dream of Egg-Fried Rice
4." Quickly wear the villain, he's a little obedient." Author: Miss Shi Sheng
The following is a detailed introduction of these novels:
1." A stranger meets snow ": Ten years ago, he was framed and fell off a cliff. He was rescued by the leader of the Qingcheng Sect and became the first disciple of the Qingcheng Sect. Ten years later, he returned to his old place but forgot everything. Because of a small sword spirit, many grudges were involved. How should he choose between love and responsibility?
2. My Game of Becoming a God in Another World: Come to Yuewen's website to read more of my works.
3." Dark Card God ": A little bit of light under the apocalypse.
Darkness and turmoil sit together.
A young man with a shocking secret rose in the apocalyptic era. Was it the collision of machinery and technology, or the impact of cold weapons and hot weapons?
The young Su Bin had awakened the card system and had given birth to the strongest buff. He had risen in the midst of turmoil and had turned the world upside down.
4." Quickly wear the villain, he's a little obedient ":[1v1][Sweet Pet]
In order to remove the curse, Jiang Zheng had no choice but to follow the system's instructions and complete the mission to remove the curse.
[System 001 is at your service!]
Jiang Zheng's eyes lit up,"Can you really serve me?"
The System replied,[…Are you kidding? I have a mission for you to complete.]
Jiang Zheng squeezed her hands,[No problem. Helping the female lead is my profession!] Saving the female lead is my responsibility!
The System was speechless."…Wait, that villain isn't your responsibility…"
Jiang Zheng thought,…I know that too!
[But, Zhengzheng, you said you would take responsibility for me!]
You can read these novels on Qidian Chinese Network.
Big Lazy and Little Lazy were the nicknames of the two children. They were very lazy. They only knew how to eat and sleep all day and never helped their mother with the housework. One summer, the mother rabbit fell ill and needed the children to go out and find food by themselves. Big Lazy and Little Lazy pushed the blame to each other and refused to go out in the end, causing their mother's illness to get worse and worse, and their food to become less and less. In the end, the mother rabbit went out to look for food and never came back. This story tells us that laziness brings bad consequences and requires hard work.
Well, in some fanfictions, Naruto might obtain the overpowered sword through a mysterious inheritance. Maybe it was left by a powerful ninja from the past and Naruto discovers it in a hidden cave or something.
Another aspect is prior knowledge or experience. In some light novels, the MC is reincarnated or transferred from another world. Like in 'Konosuba', Kazuma has knowledge from his previous life which he uses to his advantage in the new world, and this knowledge combined with his unique skills makes him overpowered in certain situations.
The hero might be overpowered due to some special abilities or powers he was born with or acquired. For example, he could have super strength, magic powers, or extraordinary intelligence. And he is overly cautious perhaps because he has experienced great losses in the past when being reckless. So now, even with great power, he still thinks twice before acting to avoid repeating the same mistakes.
It could be that the nature of the world in the light novel is very unpredictable. There could be hidden enemies or powerful forces that even an overpowered hero would be wary of. So, in order to protect themselves and those they care about, they choose to be cautious. For example, there might be ancient curses or prophecies that target powerful individuals like the hero. And the hero, being aware of these potential threats, acts with caution.