One possible plot could be Shoto struggling to control the new power. He might initially be overwhelmed by One for All's sheer strength. For example, he could accidentally cause destruction during training. But as he learns to master it, he combines his ice and fire abilities with One for All in unique ways. Maybe he creates new attacks like freezing an opponent and then using One for All - enhanced strength to shatter the ice they're trapped in.
The plot could involve Shoto facing off against a powerful villain who is a threat to his friends and family. With One for All, he has a new level of power to protect them. He could start a journey to fully understand the origin of One for All and how it relates to his own family's past. Along the way, he might meet other characters who also have knowledge about the power and they could either help or hinder his progress.
A great plot could be Shoto being chosen to inherit One for All in a different way than expected. He then has to deal with the jealousy and suspicion of his classmates. They might think he's getting special treatment. Shoto has to prove that he can use the power responsibly and for the greater good. He could start training in secret to master One for All so that when he finally reveals his new abilities, he can show everyone that he is worthy of the power.
His relationship with Midoriya would become more complex. Since Midoriya originally had One for All, there could be some tension as Shoto now has the power. But they could also bond over sharing this special ability, training together to figure out new ways to use it.
Perhaps the mask is a family heirloom of one of his friends, and Naruto is entrusted with it. He soon realizes that the mask has a mind of its own and tries to communicate with him. Naruto has to figure out the mask's purpose and how it can be used to help the village. He might face challenges from those who think the mask is a curse and should be destroyed.
In a fanfiction about Tanjiro getting sick, it could be that he overexerts himself during a mission. His body gives in and he falls ill. His comrades take him to a safe house. While he is sick, he reflects on his journey so far, his losses and his goals. Meanwhile, the others keep a lookout for any danger and also try to nurse him back to health. They might face shortages of supplies and have to make difficult decisions.
Maybe in this fanfiction, Orochimaru somehow gets hold of the Venom symbiote and tries to use it to create a powerful weapon. But the symbiote escapes and attaches itself to Naruto. Naruto then has to deal with the fact that the other villagers are scared of him because of his new, monstrous appearance. However, he shows them that he's still the same Naruto by using the symbiote's powers for good and saving a group of villagers from a group of rogue ninjas.
Well, the plot could involve Ahsoka getting drunk at a celebration on some new planet she's visiting. As she gets drunk, she starts to recall memories from her past, both good and bad. This could lead to her having deep conversations with those around her, like sharing her thoughts on the Jedi Order in a more unfiltered way than she usually would. Maybe she even stumbles upon a mystery or a secret that she wouldn't have noticed if she were sober.
Well, one possibility could be that Naruto discovers the Wabisuke in an ancient ruin during a mission. Maybe it has some kind of special power that only he can unlock because of his unique chakra. He then has to figure out how to use it without it consuming him, as it might be a very powerful and dangerous weapon.
The plot might be that an enemy steals Samehada and Naruto has to get it back. Along the way, he discovers that Samehada has a connection to an ancient and powerful clan. Naruto teams up with some members of this clan who want to reclaim Samehada as well. They face many challenges together, and Naruto uses his own skills and the power of Samehada to defeat the enemy. In the end, Naruto decides what to do with Samehada, whether to keep it or return it to the clan, depending on the bond he has formed with it.
One possible plot could be that Naruto somehow ends up in the Soul Society. There, he discovers Hyourinmaru. Maybe through some strange magic or accident, he forms a bond with it. He then has to learn to control Hyourinmaru's powers, which are very different from his chakra - based powers. He might face challenges from the Soul Reapers who initially don't trust him with such a powerful zanpakuto.
One possible plot could be that Naruto is on a difficult mission and Yamato is assigned to be his partner. They start off with some misunderstandings due to their different personalities. Yamato is more reserved while Naruto is brash. But as the mission progresses, Naruto starts to learn from Yamato's calm and calculated approach and Yamato begins to see Naruto's determination and heart. In the end, they form a strong bond and become great friends who can rely on each other in future battles.
The plot might involve Naruto being summoned to Godzilla's realm by a powerful sorcerer who wants to use Naruto's skills. Naruto is initially shocked by Godzilla's size and power. However, he quickly adapts and decides to help Godzilla. He uses his Rasengan to attack smaller threats to Godzilla while Godzilla focuses on the bigger threats. In the end, Naruto returns to his world with new knowledge and a newfound respect for the power of kaiju.