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.
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.
One possible ending could be that her sacrifice is successful and everyone she saved lives in a world filled with her memory. They might create monuments or hold annual events in her honor. Another ending could be that her death actually breaks the balance of magic in the world, leading to unforeseen consequences despite her noble intention. Or perhaps her friends find a way to bring her back in the end, using their own combined powers and the power of their love and friendship for her.
One possible plot development could be that Voldemort fully regains his power without Harry as an obstacle. The wizarding world would be plunged into complete darkness. His friends, like Hermione and Ron, might go into a deep state of despair and then form a resistance group. They would try to find other ways to defeat Voldemort, perhaps by seeking out more powerful magical artifacts or uniting with some previously neutral magical creatures.
A possible plot could be that the dragon is a new, unknown and extremely powerful species. Harry is sent to investigate it but underestimates its power and gets killed.
One possible consequence could be chaos at Hogwarts. The school has high hopes for Harry in the Triwizard Tournament. His death would shock the students and teachers. The other champions might feel guilty or be blamed. Also, Voldemort's plans related to Harry would be disrupted, as he was supposed to be a major part in the wizarding world's future battles against the Dark Lord.
One possible plot development could be how the wizarding world reacts to the loss of the so - called 'Chosen One' even as a baby. There might be widespread grief and fear among those who opposed Voldemort, as they had placed so many hopes on Harry. Another aspect could be how Voldemort's reign of terror continues without the threat of Harry Potter. He might become even more powerful and tyrannical, with no one to oppose him in the way Harry was prophesied to.
In some versions, it could be that Harry has to die to break a dark curse placed on Ginny. He discovers that his life is the key to saving her and willingly gives it up. He might have a premonition about Ginny's fate and decides that his death is the only way to change it. He then confronts the source of the curse and allows it to take his life instead of Ginny's.
Another ending could be a more tragic one. With Captain America's death, the Avengers lose their moral compass. They become disorganized and are ultimately defeated by Thanos. This would show the huge impact Cap had on the team.
One possible scenario could be that Harry is overpowered by the Basilisk. Maybe he goes alone to face it without the help of Fawkes or the Sorting Hat's sword, and the Basilisk's venom is too much for him to survive.
One possible scenario could be that Harry loses the love of his life. Maybe she was killed in a battle against dark forces, and he is unable to move on from that grief. His broken heart then leads to his own death as he slowly loses the will to live, consumed by his sorrow and memories of her.