Well, Harry could be more confident in his own power. In the normal series, he had doubts about his abilities at times. But in this scenario, if he's set on destroying Snape, he has to be certain of his magic. He would be more decisive, not hesitating to use his skills against Snape. Also, his relationships with other characters might change. Some might see him as too aggressive in his pursuit of Snape, while others might support him wholeheartedly, creating a divide among his friends.
Perhaps in the fanfiction, there is a prophecy that Snape will cause great harm to Hogwarts. Harry, being the hero, feels it's his duty to stop Snape. He starts to gather evidence of Snape's wrongdoings, which are not obvious at first. As he digs deeper, he uncovers a web of lies and deceit that Snape has spun. This leads to a confrontation where Harry uses his magic skills and the loyalty of his friends to destroy Snape's influence over the school and the other wizards. Snape might have been planning to use dark magic to take over Hogwarts, and Harry is the only one who can prevent it.
Ron and Hermione would most likely be his allies. They've always been by Harry's side through thick and thin. In this situation, they would use their respective skills, Ron's loyalty and Hermione's vast knowledge of magic, to support Harry in his mission to destroy Snape.
In such a fanfiction, perhaps Harry discovers some dark secret of Snape's that makes him decide to take action against him. Maybe Snape has been plotting something truly evil all along, and Harry finally uncovers it and has to destroy Snape to protect Hogwarts and his friends.
There very well could be. Fanfiction writers often like to explore unusual crossovers. Since both Harry Potter and Thanos are extremely popular in their respective franchises, it's a ripe area for creative exploration. However, the quality and availability can vary greatly depending on the fanfiction platforms you search on.
The Order of the Phoenix members might also back Harry. They've fought against the dark forces before and if they see that the Ministry has become a threat, they'd side with Harry. Dumbledore's old allies in the Order would believe in Harry's judgment and join him in his mission to destroy the corrupt Ministry.
Well, it's a very dark and unorthodox concept. In the original series, Dumbledore is a mentor figure to Harry. In fanfiction, if Harry were to destroy Dumbledore, it could signify a major deviation from the core values of the original story. It might be exploring themes of betrayal, a different view of power dynamics, or a radical re - interpretation of the characters' natures.
Probably not. Given that the Weasleys are beloved characters in the Harry Potter universe, a fanfiction with such a negative and extreme concept as Harry destroying them is likely to be off - putting to a large number of fans. Fans usually look for fanfictions that expand on the positive aspects of the story, like friendships and adventures, rather than something so dark and against the norm.
I'm not sure about the specific plot of this fanfiction as it sounds rather unorthodox. It could be a very dark or alternate - universe take on the Harry Potter world where Harry goes against the Weasleys for some extreme reason.
I have no idea who the author of that fanfiction is. There are so many fanfiction writers out there, and without more information it's impossible to determine.