In some fanfiction concepts, it could be due to a new, powerful jutsu he discovers or perhaps as a result of some ancient curse or blessing that is bestowed upon him.
One consequence could be that it disturbs the balance of the ninja world. The dead are supposed to rest, and by controlling them, Naruto might be messing with the natural order. This could lead to other ninja clans or villages seeing him as a threat.
In some fanfiction concepts, Naruto and Sakura might control the dead through powerful jutsu. Maybe they discover an ancient forbidden technique. For example, they could find a scroll that teaches them how to manipulate the souls of the dead. This could be a result of their continuous exploration and growth in the ninja world.
In some fanfics, it could be due to a forbidden jutsu he discovers. Maybe he stumbles upon an ancient scroll that details the process of controlling the dead.
In fanfiction, if Harry Potter controls the dead, it could completely change the power dynamics in the wizarding world. It might give him an edge in battles, as he could summon the knowledge and skills of the deceased. For example, he could get strategic advice from great wizards of the past. However, it also raises moral questions. Is it right to use the dead in such a way? It goes against the natural order in the original Potter universe.
Foxes are quite common. Given Naruto's connection with the Nine - Tailed Fox, it makes sense that in fanfiction, he might be able to control other foxes. They can be used for scouting or as distractions in battles.
One idea could be that Naruto gains some new power or jutsu that allows him to control Anko's actions in a non - malicious way. Maybe it's a form of genjutsu that he accidentally uses on her during a training session, and then has to figure out how to reverse it.
It varies from one fanfiction to another. Some fanfictions might depict Naruto as dead to introduce a new set of challenges for the remaining characters. For example, if Naruto dies, Konoha might be left vulnerable, and characters like Sasuke or Sakura would have to step up in different ways. But there are also plenty of fanfictions where Naruto remains alive and continues his journey, perhaps facing new and even more dangerous threats than in the original series.
In a 'Naruto controls snow' fanfiction, it could be that Naruto is cursed by an enemy. As a result, his chakra is somehow linked to snow. At first, he struggles to control this new power, but with the help of his friends and some intense training, he masters the ability to control snow and turns it into a powerful weapon against his foes.
In the fanfiction where Naruto controls the Tesseract, it could change the power dynamics completely. Naruto is already a powerful ninja, but with the Tesseract, he could become near - invincible. He might be able to use the Tesseract's space - bending abilities to surprise his enemies in battle. For example, he could suddenly appear right in front of them or make them disappear into another dimension. Also, he could potentially use it to heal wounds or revive the dead, if he discovers all of its powers, which would make him not just a hero in his own world but maybe in the entire multiverse of the fanfiction.