Well, character development is a big one. As Naruto uses the blood release, his personality might change or evolve. He could become more confident or more cautious. And the relationships around him also change. His friends might be in awe or a bit scared of his new power. The fanfic also needs a good plot that revolves around the blood release, whether it's to save the village, defeat a powerful enemy, or uncover some long - hidden secrets related to his power.
In Naruto fanfiction, the element of the ninja villages is quite important. Different fanfictions may focus on Konoha, but also explore other villages like Suna or Kiri. The power hierarchies within these villages can be a major part of the story. Additionally, the idea of the tailed beasts is a significant element. Writers could come up with new ways of how the jinchuriki interact with their tailed beasts or create stories about the tailed beasts' history.
Well, in many fanfictions, Naruto might start learning all elements through some unique encounters. Maybe he meets a powerful sage or a mysterious ninja who has knowledge of all elements and decides to teach him. It could also be due to some ancient scroll he discovers that holds the secrets of mastering all elements.
Well, in some fanfictions, Naruto might achieve this through intense training with powerful mentors. Maybe he travels to different hidden villages to learn from their unique elemental techniques. For example, he could go to the Mist Village to master water techniques. Another way could be through some kind of ancient power or a special inheritance that unlocks the ability to control all elements within him.
One consequence could be that he becomes a target. Other villages or powerful individuals might see him as a threat. They could try to either eliminate him or control him for their own purposes.
Well, in the fanfic, Naruto using crystal release could be part of a mission. Maybe he's in a land where crystal release is common among the enemies. He starts to study their techniques and somehow manages to adapt it to his own style. He could then use it to save his friends during a really tough fight. Like, he creates a huge crystal shield to protect everyone from a massive attack and then turns the shield into sharp projectiles to counter - attack.
In a fanfic where Naruto uses haki, it could change his relationships with other characters too. For example, if he shows this new power, some characters might be in awe of him, while others might be jealous. His training to master haki could also lead to new interactions with mentors or allies who are familiar with this power. Also, his use of haki could potentially attract the attention of new enemies who are interested in this unique ability.
One challenge could be the sheer complexity of each element. Each element has its own unique properties and techniques. For example, water element requires a different kind of chakra control compared to fire. Naruto would have to spend a lot of time mastering these differences.