In this fanfiction, Harry might snap due to the stress of being 'The Chosen One'. He could start to question the Hogwarts authorities and their methods of dealing with the dark forces. He might break some rules to take matters into his own hands and go on a solo mission to end the dark lord once and for all. This could lead to some interesting conflicts with his friends who might not agree with his rash actions at first.
Well, it could be about Harry finally losing his patience with all the constant threats and dark magic. Maybe he decides to take a more aggressive approach against Voldemort and his Death Eaters, instead of always waiting for them to make the first move.
Well, it might be that Harry snaps due to his ongoing struggle with Voldemort. After constantly being in a state of fear and having to fight for his life and the lives of his friends, he reaches his limit. He could turn against some of his friends who he feels haven't been fully supportive or understanding. His snapping could lead to a power shift in the wizarding world, as he may start to use his magic in more aggressive and unorthodox ways to protect himself and what he believes in.
One possible plot could be that Harry discovers some new information about his parents that makes him see Snape in a different light. However, instead of handling it calmly, he snaps because of all the pent - up anger and confusion. For example, if he finds out that Snape had a more complex role in his parents' lives than he thought. His snapping could involve shouting at Snape in front of the whole school, which then sets off a chain reaction of events that slowly changes their relationship from one of enmity to something more like a father - son dynamic, full of misunderstandings and reconciliations.
Well, it could be that Hinata has been pushed too far by the constant bullying or pressure in the Naruto world. Maybe she finally snaps at those who have underestimated her all along, like some of the meaner villagers or perhaps even some of her rivals during a particularly intense moment in a fight or competition.
Well, it could be about Tsuna reaching his breaking point after constantly facing difficult situations, like too many battles or personal betrayals. Maybe he snaps and decides to take a completely different approach to things, perhaps becoming more aggressive or even distancing himself from his friends for a while.
Harry Potter and Severus Snape are the central figures. However, the other Hogwarts professors could also be important. For instance, McGonagall. She might be the one who tries to calm Harry down after he snaps at Snape or she could be the one who encourages Snape to be more understanding towards Harry. Then there are the Death Eaters. If the fanfiction is set in a context where Voldemort is still a threat, the actions of the Death Eaters could impact the relationship between Harry and Snape. They could be the catalysts that force Harry and Snape to work together and ultimately strengthen their father - son - like bond.
Another possibility is that the main antagonist could be the wizarding society as a whole. If Harry has been constantly marginalized or misunderstood by the general wizarding population, he could snap and see them as the enemy. Their narrow - minded views and prejudices, like against half - bloods or Muggle - borns, could be what pushes Harry over the edge. He may then try to change or even rebel against the entire wizarding society.
Voldemort would still be a major character. After all, he is Harry's main antagonist. If Harry snaps, it would likely be in relation to his ongoing battle with Voldemort. And the Death Eaters, as Voldemort's followers, would also be involved. They would be on the receiving end of Harry's new, more aggressive stance, and their reactions would shape the story further.
Well, it could be that Naruto finally snaps due to the continuous betrayal or loss he has faced. He might turn against his former friends or village. For example, if he discovers some dark secrets about the village that have been hidden from him all along, this could be the final straw. He could then start his own journey, not as a hero of the village but as a sort of anti - hero, challenging the existing order.
It could start with a build - up of small incidents. For example, the Dursleys constantly belittling him even after he has proven himself in the wizarding world. Then, one major event, like the Dursleys trying to sell his magic items or preventing him from going back to Hogwarts, causes Harry to snap. His killing of the Dursleys could then lead to a search for redemption or a fight against those who want to punish him unjustly, as he was pushed to his limits by their cruelty.
In fanfiction, if Harry Potter snaps his wand, he might lose a great deal of his magical power. His wand is his primary tool for casting spells, so without it, he'd be in a very vulnerable position. He could start to explore alternative forms of magic or seek out a new wand, perhaps through some extraordinary adventure. This could also lead to him relying more on his friends and the skills he has developed outside of wand - based magic.