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.
Some forums dedicated to Dragon Ball Z also often have sections for fanfictions. These can be a great source for overpowered Goku fanfictions. Members of the forum sometimes write and share their own stories. You can also ask for recommendations in these forums. Just be aware that the quality and content can vary widely, so you might need to do some sifting through to find the really good overpowered Goku fanfictions.
To write an overpowered mc fanfiction, start with a strong concept for the character's power. It could be something as simple as being able to fly at supersonic speeds or as complex as having the ability to rewrite reality. Then, build a cast of supporting characters around the mc. These characters can react to the mc's power in different ways, some in awe, some in fear. The story should also have a goal for the mc, whether it's to save the world, find a lost family member, or just to find a place where they can belong despite their power.
Well, there are a few dedicated SCP fan forums and communities where you might find such stories. Sometimes, authors post their works on these platforms. Just make sure to follow the community rules when accessing and interacting.
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.