" I Raise Tailed Beasts in Naruto World " might fit the plot of the novel you mentioned. The protagonist transmigrated to the Naruto World and awakened the Tail Beast System. One of the scenes was feeding Nine-Tailed in the mental world. I recommend you to read this novel. I hope you will like it.😊
" Naruto: My Psychic Beast is Billion Strong " is a novel that you must not miss. Its plot revolved around the protagonist Naruto who accidentally transmigrated to the Naruto World and became Naruto Uzumaki. He was also bound to the Psychic Beast System at the beginning. After signing a contract with the Psychic Beast, he could obtain the power of the Psychic Beast. This novel added a lot of fantasy elements to the story and had a more special plot than other Doujinshi novels. I hope you will like this novel.
Obviously, Naruto is the main character as the story focuses on his growth of the nine tails. Kakashi could also be an important character. He might be the one guiding Naruto in controlling his new power, given his experience and knowledge. Sakura could play a role too, perhaps as a healer in case Naruto gets injured during his power - growth process.
Sometimes, other characters from the Naruto universe might also play important roles in these fanfictions. For example, Kakashi could be involved as Naruto's mentor, giving advice on how to better communicate with the Nine - Tails. Or Sakura might be there to support Naruto in his journey of befriending the Nine - Tails, even if she doesn't directly interact with the tailed beast.
Perhaps an ancient evil spirit that was once sealed away by the nine - tails long ago. Now it senses the nine - tails' presence in Naruto and wants to take revenge on it by destroying Naruto. This antagonist could have powers that are a match for Naruto and the nine - tails combined.
Naruto's character might develop a deeper sense of self - awareness. With the Nine - Tails Cloak, he realizes he has a greater power and responsibility. He becomes more cautious in using it, understanding the consequences of losing control.
I recommend " The Sword of Muye Suppresses the World " to you. The protagonist of this novel carries the dnf Ghostblade System and is reborn into the world of Naruto. He becomes the young boss of the Ninja Mandian Hall in Muye Village and shows off his Ghostblade skills. This book is finished, you can rest assured to collect it. I hope you will like this fairy's recommendation.😗
😋I recommend Naruto's Journey to You. This is a wonderful Naruto Doujin novel written by the author, Xing Liyou. The main character, Kageyama, was reborn as a nine-tailed human pillar, but he did not complain about fate like Naruto. Instead, he embarked on a journey to find his own goal. In the end, he also shocked the entire Naruto world and became a legendary figure in the history of Naruto! I hope you like this fairy's recommendation. Muah ~😗
😋I strongly recommend Naruto: Dark Dawn, a Doujin novel written by the author, Doomsday Cucumber. The main character's soul had somehow transmigrated to the center of the second ninja battle, an ordinary youth named Chiba from the Country of Rain. There was no cheat in this novel, but it did have the most sincere feelings and the most trustworthy companions. Although the main character did not have a cheat, he had already made himself even more powerful than Long Aotian. Interested babies can go and find out! I hope you like my recommendation.😗
Sasuke could be a main character in a Naruto 11 Tails Fanfiction. He has always been Naruto's rival and equal in many ways. His skills and knowledge of the ninja world could be crucial in dealing with the 11 - tails. Maybe he would have a different perspective on how to handle the situation compared to Naruto.
Maybe through new jutsu or abilities. The fanfiction could give Naruto some unique power that allows him to communicate or negotiate with the Nine - Tails on a different level. He could use this power to show the Nine - Tails a different perspective, like the potential for harmony between them instead of constant struggle.