Sometimes, it's a way to show the harsh reality of the story's setting. If it's a war - themed novel, killing many characters can depict the horror and destruction of war. Like in 'All Quiet on the Western Front', the large number of deaths among soldiers effectively conveyed the brutality of World War I.
One reason could be to create a sense of extreme tragedy or futility. By eliminating all the characters, the author might be trying to show that in the world of the novel, there is no hope and all are doomed. It could also be a very extreme form of making a statement about the futility of life or the overwhelming power of certain forces, like a cruel and inescapable fate or a devastating event such as a global catastrophe that no one can survive.
Perhaps the elephant was in pain or sick. When animals are not well, they can act unpredictably. So, if the elephant had an injury or an internal illness, it might have lashed out at the woman without really intending to kill her. Another reason could be that the elephant was protecting its food source or its young. Elephants are very protective of their calves and their feeding areas. If the woman was perceived as a threat to either of these, the elephant could have attacked.
One reason could be the tiger's territoriality. If the lady entered the tiger's territory, it might attack to defend it.
Maybe some writers want to explore extreme character deviations. They might be interested in creating a shock factor by making a beloved character like Ahsoka do something so heinous. It could also be an attempt to explore a very dark, alternate universe where all the good characters turn bad.
It could be due to a great tragedy. For example, if all his friends were killed and he was filled with rage and revenge. In that state of mind, he might become a killing machine, just focused on destroying those who wronged him.
One possible reason could be that during sleepwalking, the brain's normal inhibitory mechanisms are disrupted. So, the sleepwalker may act out violent dreams or impulses without the normal self - control. Another reason might be related to underlying psychological stress or trauma that surfaces during the sleepwalking state.
One reason could be to create a sense of shock or surprise. It makes the story more unpredictable. For example, in 'Game of Thrones', the sudden death of Ned Stark shocked readers and viewers alike, completely changing the direction of the story.
One reason could be extreme physical exhaustion. For example, if a character has been running for a long time to escape from danger, like in an adventure novel where the hero is being chased by villains through a forest for days without proper rest or food. Another reason might be due to emotional shock. Say, a character discovers that a loved one has betrayed them or has passed away suddenly. In a mystery novel, a detective might pass out when he finally uncovers a particularly grisly truth that he was not prepared for. Also, it could be because of a physical injury. In a war novel, a soldier who gets seriously wounded might pass out from the pain and blood loss.
Some creators might want to explore a darker side of Naruto's character. Maybe they're tired of the always - positive and heroic Naruto and want to see what he'd be like if pushed to the extreme.
One possible reason could be that they got into a relationship against their families' wishes. In some cultures, family - arranged relationships are the norm, and any deviation can be seen as a threat to family honor.