One challenge could be the chakra consumption. Shadow travel might require a large amount of chakra, and Naruto has to learn how to manage it. If he uses it too often or for long distances, he could run out of chakra in the middle of a mission or a fight.
Controlling the destination accurately can be a big problem. Since it's a new ability for him, he might end up in the wrong place. He could appear in the middle of an enemy camp instead of the safe location he intended. Also, if the environment he travels to has strong anti - shadow or anti - chakra defenses, it could disrupt his travel and even cause harm to him.
Well, in some fanfictions, Naruto might learn the shadow travel ability through a special training with a hidden shinobi. Maybe this shinobi has a unique jutsu related to shadows and decides to teach Naruto as he sees Naruto's potential.
Well, Naruto might face environmental challenges. For example, if the toddler is in a swampy area or a place with a lot of quicksand. Naruto has to navigate through these difficult terrains while protecting the toddler. Also, if there are other threats around like poisonous plants or insects, he has to be aware of them too. He can't just focus on getting the toddler out, but also has to ensure their safety during the whole process. This requires his full attention and all his ninja knowledge.
One challenge could be facing powerful new enemies. In fanfiction, authors often create unique and formidable foes for Naruto. These enemies might have strange powers or abilities that Naruto has never encountered before, forcing him to quickly adapt his fighting style. Another challenge could be the moral dilemmas. He might have to make tough decisions in the chaos of war, like whether to sacrifice a few to save many.
One challenge could be that the heartless have a very different nature compared to the beings Naruto is used to dealing with. Their lack of emotions might make it difficult for him to find a way to connect and control them.
In the fanfiction, another challenge Naruto might face is dealing with any mind - control or brainwashing techniques the enemy may have used on Ino and her squad. If they are turned against Naruto, it becomes a more complicated situation. He not only has to free them from the physical danger but also has to break the mind - control. And if the enemy has allies that keep coming, Naruto will have to fight continuously while also protecting Ino and her squad, which requires a great deal of stamina and strategic thinking.
One challenge could be the sheer amount of chakra it requires. Controlling all elements might demand a vast amount of chakra, and Naruto may find himself quickly drained in battles. For example, if he tries to use all elements simultaneously, he could run out of chakra and be left vulnerable.
He also has to deal with the public perception. People who are afraid of the nine - tailed fox might start to shun or even attack Naruto. And in battles, his enemies might target his connection to the nine - tailed fox, trying to force him to transform and lose control. He needs to be constantly vigilant about this.
One challenge could be getting the necessary resources. Uzushiogakure was destroyed long ago, so finding materials to build the village again would be tough. He might have to negotiate with other villages for supplies.
One challenge could be dealing with jealousy from other villages. His godlike powers might make other villages feel threatened. Another issue could be managing the different personalities and abilities of the people who come to live in the new village. He has to make sure everyone gets along.
Another problem might be the lack of proper resources. Even if Naruto has the ability to heal, he may not have all the necessary herbs or medical equipment. In the world of Naruto, some healing requires specific items. If they are in a remote location or in a battle - torn area, getting these resources could be a huge hurdle.