The Yamato sword could add a slashing and stabbing element to Naruto's fighting style. Instead of just relying on his punches and Rasengan, he can now make quick and precise strikes with the sword, catching his enemies off - guard.
Yamato might first be a bit shocked. But then he'd probably try to calm Naruto down. He could use his wood - style jutsu to create a peaceful environment, like making a small forest around them to soothe Naruto.
Yamato might first try to use his calm and steady presence to soothe Naruto. He could place a hand on Naruto's shoulder and speak in a gentle voice, telling him to take deep breaths.
Some Naruto fan forums may also be a great place to find such fanfictions. These forums usually have dedicated sections for fanfiction. You can browse through the threads or create a new one asking for 'Naruto has Yamato' fanfictions. Just be sure to follow the rules of the forum while doing so.
Yamato might show his concern by constantly checking on Naruto's condition. He could be seen sitting by Naruto's bedside, feeling his forehead for fever regularly.
Perhaps the Yamato sword was once owned by an ancient Uzumaki clan member. Naruto, being an Uzumaki, has a natural affinity for it. In the fanfiction, he could learn ancient techniques related to the sword from hidden scrolls left by his ancestors, and use these new skills to protect the village from a new and powerful threat.
In a fanfiction, Naruto, Yamato, and the katana could be part of a quest. For example, they are on a mission to return the katana to its rightful place. Along the way, they face many enemies and Naruto uses his unique skills while Yamato uses his wood - style jutsu to protect the katana and each other.
In this fanfiction, Naruto's panic attack might be caused by the pressure he feels. He has so many responsibilities, like protecting the village and his friends. Yamato might be a trigger because Naruto doesn't want to show weakness in front of him, but the stress gets to be too much.
Naruto might be in awe of the battleship Yamato at first. He could use his chakra to enhance the ship's speed or power in some way. For example, he could transfer some of his chakra to the engines to make it move faster.
One possible plot could be that Yamato, with his calm and disciplined nature, instills in Naruto a better sense of self - control. Naruto might learn wood - style techniques earlier. He could also grow up with a stronger connection to nature due to Yamato's influence. For example, Naruto might be more in tune with the forest around Konoha and use it to his advantage during missions.