In fanfiction, Naruto could face a challenge in terms of communication. He has likely grown and changed during his training, and he may find it difficult to convey his experiences and new perspectives to his friends and family in Konoha. His new skills may be so advanced that it's hard for others to understand how to work with him in combat situations. Additionally, there could be a cultural shift within Konoha during his absence. Naruto might need to adapt to new values or ways of thinking in the village, which could be a struggle as he tries to fit back in while also remaining true to his own growth and development.
One challenge could be readjusting to the village life. After intense training in a different environment, the daily routines and social norms of Konoha might seem strange. Also, he may face jealousy from some of his peers who haven't advanced as much in their skills during his absence. Another challenge could be dealing with the new threats that Konoha might be facing, and having to prove himself all over again to the village elders that his new skills are useful for the village's protection.