I'm not a reader of Naruto novels or web novels. Naruto was a Japanese manga, and the title of Naruto's Life for a Long Time could refer to another work. If you can provide more context, I can try my best to answer your questions.
In 'Naruto Life as a Devil' fanfiction, the plot could center around Naruto being sent to a different dimension where he is turned into a devil. In this dimension, there are different rules and power hierarchies. He may have to form alliances with unlikely characters in order to survive. He could also be on a quest to find a way to return to his normal self and the Konoha he knows, all while learning to control his devilish powers which might include things like shadow manipulation or enhanced physical abilities.
Perhaps in this fanfiction, Naruto remembers a past life where he was part of a different ninja clan. This could lead to him having skills or knowledge that no one in the current Naruto universe has. For example, he might remember a unique jutsu from his past life and try to recreate it in his present life. He could also struggle with the identity crisis of feeling like he belongs to two different worlds or identities.
One interesting plot could be Naruto getting a second chance at life and using his knowledge from his first life to prevent the Fourth Great Ninja War. He could focus on training his friends earlier and revealing Orochimaru's plans much sooner. This would change the entire course of the shinobi world and lead to new alliances and power dynamics.
One possible interesting plot could be Naruto finding out that the 'game' has hidden quests related to his family's past. For example, he discovers a quest that leads him to learn more about his mother's clan and the special powers they held. This could add a whole new layer to his character development as he tries to master these newfound abilities within the game - like framework of his life.
The main plot of Naruto Shippuden's life story is about Naruto's growth. He goes from a somewhat naive and underestimated ninja to a powerful and respected one. He faces many powerful enemies like Pain. He also tries to bring Sasuke back to the village. His journey is filled with battles, self - discovery, and learning new jutsu to protect his friends and the Hidden Leaf Village.
One possible plot could be them adjusting to living together. Naruto might be a bit messy and Ino would be trying to keep the house in order. They could also have arguments about how to raise their future kids, with Naruto being more lenient and Ino stricter.
The fanfic could center around a self - insert character who is a huge Naruto fan in their real life. One day, they wake up in Naruto's life, literally. They experience his daily routine, his training sessions, and also his emotional moments. For example, they could be with Naruto when he first tries to master the Rasengan or when he faces off against Sasuke at the Valley of the End.
One plot idea could be that Naruto has a secret training regime away from the village. He discovers a hidden cave where he finds ancient scrolls that teach him unique jutsu not known in the village. This new knowledge makes him even more powerful and he has to keep it a secret as he doesn't know if the jutsu are safe or how the village will react.
Well, it could be about a character achieving an ultimate life form through some unique training. Maybe they discover a new chakra mode that transforms them into an ultimate life form with incredible powers like super speed and strength.
One possible plot could be that Naruto somehow stumbles upon the Book of Life. Maybe he's on a mission in a mysterious land and finds it. The Book of Life has the power to rewrite destinies, and Naruto, being Naruto, wants to use it to bring back his fallen comrades like Jiraiya. But he soon realizes that meddling with the Book of Life has unforeseen consequences. It could start to distort the balance of the ninja world as the fates of many are intertwined. Villains might also get wind of it and try to snatch it from Naruto to fulfill their own evil desires.