In this fanfic, Naruto's ability to control Grimm could be related to his strong willpower. He is known for his determination in the Naruto series. So, when faced with the Grimm, he could somehow tap into their essence and take control. He might start training the Grimm, much like he trained with his ninja friends. He could teach them basic commands using his chakra, and as he gets better at it, he could even make the Grimm perform complex tasks like scouting or guarding areas.
The plot could also involve Naruto using his control over the Grimm to bridge the gap between different factions in the Grimm world. Just as he tried to bring peace in his own ninja world, he could do the same here. He may use his controlled Grimm to show other groups that these usually feared creatures can be tamed. This could lead to a new form of cooperation, with Naruto at the center, using his Grimm-controlling powers to create a more harmonious Grimm world.
Well, one possibility could be that Naruto enters the world of Grimm. Since he has his ninja skills, he might initially be confused by the Grimm but then start using his jutsus to control them. Maybe he uses his shadow clone jutsu to surround and corral the Grimm, turning them into an army of his own. He could use his chakra to influence their behavior, like making them attack his enemies instead of the innocent.
One possible plot could be that Naruto discovers a new jutsu that allows him to control scorpions. He then uses this ability to gather intelligence in the Hidden Sand Village where scorpions are common. The scorpions could act as his little spies, reporting back to him any suspicious activities.
Well, it could be that Naruto somehow gets transported to the RWBY universe and has to deal with the Grimm. Maybe he uses his ninja skills to fight them off. For example, his shadow clone jutsu could be used to confuse the Grimm while he attacks from another angle.
If Naruto creates Grimm fanfiction, perhaps he would imagine himself as a Huntsman in the Grimm world. He might use his shadow clones to outnumber the Grimm. His ninja skills like the Rasengan could be transformed into some sort of super - attack against the Grimm. Also, he could bring the concept of chakra into the Grimm universe and have the characters use it to fight the dark creatures.
I'm not sure exactly as I haven't read this specific 'naruto first grimm fanfic'. It could be a fan - made story that combines elements from Naruto and Grimm. Maybe it has Naruto characters in a Grimm - like world or vice versa.
One possible plot could be that Naruto, through some sort of magical or cross - dimensional event, ends up in the One Piece world. His ability to control the ocean could startle the pirates and marines alike. Maybe he teams up with the Straw Hat Pirates. He could use his ocean - controlling powers to help them navigate through dangerous waters, like the Calm Belt. He might also use it to fight against powerful enemies, like the Yonko, by creating huge tidal waves or whirlpools.
Well, a cool plot might be that Naruto uses the Nine - Tails to travel to different dimensions. He could explore places that were previously unknown and discover new powers or allies there. Also, in the fanfic, he could use the Nine - Tails' chakra to heal the land that was damaged by previous battles. This would show his growth not just as a fighter but also as a protector of the village and its surroundings.
One idea could be that the female Grimm is an outcast among her kind. Jaune, with his sense of justice, tries to understand her instead of immediately fighting. They form an unlikely alliance and learn from each other, with Jaune teaching her about the value of life and she showing him the secrets of the Grimm world in return.
In a fanfic like this, there could be a lot of conflict. The Grimm's presence could be seen as a threat by the Hidden Villages. Naruto would then have to convince everyone that his pet Grimm is not a danger. Also, the Grimm might have special abilities that Naruto could use in battles or to solve problems in the village. For example, if the Grimm can fly, Naruto could use it to quickly reach far - off places or spy on enemies. And Naruto could also teach the Grimm some of his ninja values, like loyalty and perseverance.
One interesting plot development could be Naruto using Kyuubi's power in a new and unexpected way in a battle. For example, he might be able to combine it with his Rasengan in a more powerful form that no one has ever seen before. This could give him an edge against a really strong enemy.
Another idea is that Tamamo is somehow connected to the Nine - Tailed Fox inside Naruto. This connection could lead to a journey where they both have to explore Naruto's inner self. Along the way, they encounter various challenges related to Naruto's past traumas and the power of the Nine - Tails. Tamamo's presence could help Naruto better understand and control the power within him.