Well, in this fanfiction, an ending might be that Hinata, in her grief, leaves the village for a while to find herself. When she returns, she has become stronger and more confident. She then devotes her life to making the village a better place, just as Naruto would have wanted. Another ending could be that the whole village unites even more tightly after Naruto's death, with Hinata at the forefront of this unity, as she was the last person Naruto protected.
He would feel a deep sense of guilt, thinking that if he had been stronger or more aware, he could have saved her. Naruto might also start to cherish the memories he had with Hinata more, and this could change his personality a bit, making him more somber at times. He would probably vow to protect the things that Hinata held dear, like her family and the village.
In this type of fanfiction, Naruto's death while protecting Hinata could be the turning point of the whole story. It could cause a shift in the power dynamics of the village. Hinata, on the other hand, would be deeply affected. She might become more withdrawn at first, but then gradually find the strength within herself. His death could also inspire the younger generation to be more like Naruto, always ready to sacrifice for the ones they love.
One possible storyline could be in a dark AU (Alternate Universe). Maybe there's a powerful new enemy that targets Hinata specifically because of her connection to Naruto. This enemy could have some sort of vendetta against the Hyuga clan and sees Hinata as the key to their downfall. Naruto is then left to deal with the grief and also find a way to avenge her death, which could lead to a whole new arc of him exploring darker powers or making some difficult moral choices.
A common scenario in such fanfictions is that Hinata sacrifices herself in a war - torn situation. For instance, in a great ninja war, Naruto is the key to victory but is targeted by the enemy's most powerful forces. Hinata, with her unwavering love for Naruto, jumps in front of a massive attack aimed at Naruto, knowing full well that it will cost her life. This selfless act then serves as a major turning point in the story, inspiring Naruto and his comrades to fight even harder.
A tragic ending could be that Harry's death leads to the fall of the good side in the wizarding war. His friends, demoralized by his loss, are unable to fight back effectively against the dark forces.
One possible storyline could be that in a major battle against a powerful enemy, Hinata jumps in front of Naruto to take a fatal blow meant for him. This could lead to Naruto going into a rage and unlocking a new level of power in his grief. He might then defeat the enemy single - handedly, vowing to carry on Hinata's will.
One possible plot could be that an ancient evil is awakened and sets its sights on destroying Konoha. Naruto, as the Hokage or a respected ninja, rallies all his friends and allies at first. However, as the battle progresses, he realizes that the only way to truly stop this evil is by giving his own life. So he makes the ultimate sacrifice, using his chakra to seal the evil away forever, thus protecting Konoha at the cost of his life.
One possible plot could be that Naruto and Haku are in a situation where an extremely powerful enemy attacks. Naruto, being the selfless hero, jumps in front of Haku to take a fatal blow. Haku is then left with the guilt and determination to carry on Naruto's will. She might vow to bring peace to the ninja world, just as Naruto had always dreamed. This could lead to Haku joining the Hidden Leaf and trying to bridge the gap between different ninja clans in Naruto's memory.
There could be. Fanfiction is a vast and diverse world where all kinds of crossovers and unusual plotlines can exist. However, considering that Naruto and Bleach are two separate and distinct anime universes, it's not something that would be part of the official storylines. But fans often create unique scenarios, so it's possible that someone has written such a fanfiction, though I haven't come across it myself.
The appeal lies in the potential for romantic development. In many fanfictions, Naruto protecting Hinata is a stepping stone to their romantic relationship. It creates a lot of tension and sweet moments. Naruto's heroic acts make Hinata admire him more, and Naruto starts to see Hinata in a new light. These stories can also show how their relationship affects the other characters in the Naruto world and the overall story arc of the fanfiction.