I'm not entirely sure about the full story of 'tengoku daimakyou' as it may be a relatively niche or complex piece. It could involve a unique setting, a set of characters with their own goals and relationships, and a series of events that unfold in that particular fictional world.
I'm afraid I can't provide a proper brief introduction to the full story of tengoku daimakyou as I'm not very familiar with it. It could potentially involve a fantastical world and characters with their own quests.
I'm not entirely sure as 'doku wo kurawaba sara made' seems rather unclear. It could potentially be some sort of very specific or made - up Japanese - influenced phrase. 'Novel' here might imply that it has something to do with a new or original idea in a story - like context, but without more context it's really hard to say for sure.
An older, more experienced ninja from a hidden village that specializes in needle - based jutsu could become his mentor. This ninja could have unique insights into the art of using needles, teaching Naruto different formations and strategies for using them in battle.
It's hard to say without reading the fanfic, but it could be characters like Sasuke. Since Sasuke is Naruto's rival, he might be involved, either competing with Naruto over the use of the Raijin no Ken or joining forces with him. Kakashi is also a likely character to be in it as he has knowledge about many ninja techniques and could play a role in guiding Naruto in using the weapon.
One antagonist could be a corrupted version of one of Naruto's old friends. Maybe they were influenced by some dark force and now have powers that rival Naruto's. They would oppose Naruto not only because of the power of the kyoketsu shoge but also due to their twisted view of the ninja world. Also, there could be a group of interdimensional invaders who see Naruto's power and the kyoketsu shoge as a threat to their plans of conquering the ninja world. They would use their advanced technology and unique abilities to try and defeat Naruto.
The villain in the fanfic could also be considered a main character. If Naruto is using Shiki Fuujin, it's probably against a powerful enemy. This enemy's motives and power level would play a crucial role in the story and how Naruto decides to use the jutsu.
It could be an old hermit who has been living in seclusion. This hermit has mastered crystal release and sees potential in Naruto. He decides to pass on his knowledge to Naruto, seeing him as a key to bringing peace to the ninja world.
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.