Perhaps there is a cross - over where Naruto as the Seventh Hokage meets a powerful villain from another fictional universe. He has to combine his ninja skills with his diplomatic abilities as Hokage to deal with this new threat. This would not only test his physical strength but also his leadership and strategic thinking.
Another idea is that Naruto in his role as the Seventh Hokage is transported to a world where ninjas are extinct, but there are other super - powered beings. He has to find a way to prove the value of the ninja way and also learn from these new beings to bring back what he has learned to his own world.