Well, it could be that Naruto discovers these ancient bugs during one of his missions. Maybe they have some special powers like being able to control chakra in a unique way. He might have to figure out how to deal with them, whether to use them for good or keep them from falling into the wrong hands.
The bugs could make Naruto more cautious. Since they are ancient and might be dangerous, he would have to think before acting. This would be a new side of him as he's usually quite impulsive.
To fix character power level bugs, study the Naruto canon carefully. Make sure each character's abilities are in line with what was established in the original series. For plot holes, go back and re - read your story to find the parts that don't connect and add the necessary explanations. If there are jutsu or clan ability misinformation bugs, do more research on the Naruto wiki or re - watch relevant episodes.
Perhaps it's an ancient artifact with power. It could be a weapon like a sword or a staff that has been enchanted with some sort of magic. This power could enhance Naruto's physical abilities and give him an edge in battles. When he wields it, he might be able to access special techniques related to the artifact.
He might meet an old hermit who has been guarding the temple for centuries. The hermit could have valuable knowledge about Naruto's parents or some secret ninja arts.
He might meet an ancient sage who has been sleeping in the ruins for centuries. This sage could have a vast amount of knowledge about chakra and the ninja arts that Naruto could learn from.
One possible plot could be that Naruto discovers an ancient technology in a hidden cave. Maybe it's a powerful weapon that was used in a long - forgotten war. He then has to figure out how to use it without it falling into the wrong hands. He might seek help from his friends like Sasuke or Sakura to understand the technology better.
He might discover some long - lost jutsu. Ancient labs could hold secrets to powerful ninja techniques that have been forgotten over time. Maybe he'll find scrolls with unique chakra - based abilities or old - fashioned weapons with special powers.
Well, Naruto might discover some long - lost jutsu in that ancient library. Maybe there are scrolls that hold the secrets to new and powerful ninja techniques that no one has used in ages.