Well, he might train with new jutsus. For example, he could learn some powerful wind - style techniques. Then on his return to Konoha, he may face challenges like dealing with the villagers' reactions. Maybe some still don't trust him fully even after his training.
Well, in the 'naruto trains and returns to konoha fanfic', Naruto is the central figure. For his training, he could meet some new characters who are experts in certain ninja arts. But in Konoha, all his old comrades will be there. Shikamaru, who is known for his intelligence, might be involved in planning something related to Naruto's return. Ino could be there too, perhaps using her mind - related jutsus to help in some way. And of course, the old sages or elders of Konoha would also be present to assess Naruto's growth and the impact of his return on the village.
The 'naruto returns to konoha fanfic' might focus on Naruto's relationships. For example, his relationship with Sakura could be explored further. He might come back to Konoha and realize his true feelings for her, or there could be some unresolved issues between them that need to be sorted out. Also, his bond with Kakashi and the other villagers would be re - established in a new light, as he has changed during his time away.
It could be a rogue ninja from a neighboring village who has a vendetta against Konoha. This ninja might see Naruto's return as an opportunity to take on the strongest ninja in Konoha and prove his own strength.
In some fanfictions, Naruto might return to Konoha to a cold reception because the villagers still hold grudges from his past. Maybe they haven't fully accepted his power or the chaos he sometimes brought. For example, they could be afraid of his Nine - Tails power flaring up again and causing destruction.
It could be a rogue ninja who has been secretly building power while Naruto was away. This rogue ninja might have a vendetta against Konoha and sees Naruto's return as a challenge to his plans. So he directly confronts Naruto to prove his own strength.
The fanfiction could focus on Naruto's married life in Konoha. Maybe his wife is a powerful ninja in her own right. Together, they could train the next generation of Konoha ninjas. Their relationship could be a source of inspiration for the young ninjas. Naruto's return with his wife could also bring new diplomatic relations to Konoha if his wife has connections to other villages.
Well, one possibility is that Naruto's son is very powerful and has unique abilities. When they return to Konoha, the villagers are both amazed and a bit worried about this new generation of power. Naruto might have to deal with the elders who are cautious about his son's potential. And his son could start making friends quickly with the kids in Konoha, like Boruto did in the original series.
It's possible that the child is an orphan Naruto found. Naruto, having known the pain of being alone as a child, decides to take the orphan under his wing. He brings the child back to Konoha to give it a home and a family within the village.
In this fanfiction, perhaps the child is Naruto's own. Maybe he had an adventure away from Konoha and met someone special. The child could be a symbol of his growth and newfound family. He returns to Konoha with the child to introduce it to his friends and show how he has changed.