In such a fanfiction, perhaps Harry's friends are jealous of his newfound powers or popularity within the wizarding world. So they spread rumors about him being untrustworthy. As a result, Harry is shunned by many in the community. He has to embark on a solo journey to prove his innocence and in the process discovers who his true friends really are.
In a fanfiction where Naruto is betrayed by his friends, it could start with jealousy. Suppose Naruto gets a great power or a special recognition. His friends, feeling overshadowed, might be tricked by an evil force into thinking Naruto is using them. So they betray him, which makes Naruto realize that he has to rely on his own strength and find new allies who truly understand him.
In such a fanfiction, perhaps the parents were forced to betray Harry due to some dark magic or a powerful enemy threatening them. Maybe they had to give up Harry to save the wizarding world from an even greater evil.
Well, one possible plot could be that his family wrongly accuses Harry of using dark magic without proper evidence. They then shun him and spread false rumors about him in the wizarding community, leaving Harry feeling isolated and betrayed.
Well, one reason could be jealousy. Maybe his friends envy his fame or special abilities. Another could be misinformation. If they are fed false information about Harry, they might turn against him. For example, if someone convinces them that Harry is secretly working for the enemy.
The Ministry of Magic could also be the main antagonist in this case. If the Ministry is corrupted or under the influence of dark forces, they could manipulate Harry's friends. They might convince his friends that Harry is a danger to the wizarding world order, and his friends, being naive or misinformed, end up betraying him.
One possible reason could be jealousy. Maybe his friends become envious of Harry's growing powers or popularity. For example, if Harry is suddenly getting all the attention in their magical community, his friends might feel left out and start to resent him, leading to betrayal.
Well, Harry might feel extremely isolated at first. He has always relied on his friends, and this betrayal would be a huge blow. Draco could initially be a bit smug about it, but then as he sees Harry's pain, he starts to feel sympathy. This could be the start of their relationship development.
At first, Harry would be in disbelief. He would think it was some sort of joke or misunderstanding. But as the reality sets in, he would become a bit of a loner. He'd still have his sense of right and wrong, so he might continue to fight against the dark forces on his own, all the while hoping that his friends would come to their senses and realize they made a huge mistake in betraying him.
Well, usually in such fanfictions, Harry might face a lot of emotional turmoil and have to find his way alone to overcome the betrayal and the challenges that come with it.
In a 'Twilight Betrayed by Her Friends' fanfiction, it could be that Twilight's friends become jealous of her powers. They feel overshadowed by her abilities and knowledge. So they start to undermine her at every turn. For example, they might ruin her chances of getting a special magical promotion or getting into an exclusive magical study group. Twilight is heartbroken at first but then decides to prove herself without their support and in the process, she might find new friends who truly appreciate her for who she is.