Physically, Naruto can use his Rasengan or other powerful jutsus to fend off enemies attacking Boruto. His combat skills are top - notch, and he won't hesitate to engage in battle to keep Boruto safe.
One heartwarming scene could be when Naruto uses his shadow clones to surround Boruto in a dangerous situation, like when they are facing a powerful enemy. The clones act as a shield, showing Naruto's determination to protect his son at all costs. Another could be Naruto teaching Boruto a new jutsu privately, passing on his knowledge and skills as a way of protecting him in future battles.
There might be a fanfiction where Naruto has to protect the village from a natural disaster-like situation that was actually caused by a dark jutsu. He uses his chakra to hold back the oncoming destruction and at the same time, he organizes the villagers to evacuate safely. In this story, his leadership skills shine as much as his combat abilities.
Naruto's character can develop in his combat skills in a more nuanced way in fanfiction. Instead of just relying on brute force, he might start to master some ancient and forgotten jutsus to better protect the village. He also learns to control his emotions better during combat situations, understanding that a rash move could endanger the entire village.
In the 'boruto kills naruto fanfiction', a motive could be a power struggle. Boruto might believe that Naruto's power is holding back the village's growth or his own potential. He could think that by eliminating Naruto, he can bring about a new era of power in the Hidden Leaf. Also, it could be out of desperation. If Boruto is in a situation where he believes that killing Naruto is the only way to save someone he loves, like his mother or a friend, he might take such a drastic step.
Maybe it's the high expectations that Naruto has for Boruto. Naruto is a hero, and he might unknowingly put a lot of pressure on Boruto to follow in his footsteps. Boruto could be scared of not being able to meet those expectations.
They could start by having an honest conversation. Naruto could sit down with Boruto and just listen to his fears without judgment. This would be a first step in building a better relationship.
In a fanfiction where Naruto protects Ayame, it could be an exciting adventure. Maybe Ayame is in danger from rogue ninjas. Naruto, with his strong ninja skills and determination, jumps in to safeguard her. He might use his shadow clone jutsu to confuse the enemies and then his Rasengan to defeat them, ensuring Ayame's safety.