Yes, in some of those fanfictions, the evidence could be things like Snape's long - standing protection of Harry. The idea is that this protection might be more than just a sense of duty to Lily. It could be a fatherly instinct. Also, some fanfics might play with the idea of a magical spell or potion that changed the apparent paternity. But remember, this is all part of the fanfiction world and has no basis in the official 'Harry Potter' canon which firmly states that James Potter is Harry's father.
In some fanfictions, they might create evidence like Snape secretly protecting Harry more out of a fatherly love. For example, his constant watch over Harry at Hogwarts could be seen as more than just a teacher - student relationship. But in the original books, there is no such indication.
Fanfictions often take creative liberties. In the case of 'madara is naruto's father fanfiction', the evidence might be as flimsy as a shared look or a similar power that the author forces to be a connection. But remember, this is all in the realm of fan - created stories and has no basis in the real Naruto lore.
In fanfiction, evidence could be things like Giovanni having a soft spot for Ash that other characters don't notice. The author might write that Giovanni has some knowledge about Ash's past or abilities that seem to suggest a closer relationship. But this is just for the purpose of the fanfiction. In the canonical Pokemon world, Ash's father has not been officially revealed as Giovanni.
Well, in the 'pokemon red is ash's father' fanfiction, the evidence might be quite tenuous. It could be something like Red's influence on Ash's journey in a very indirect way. Maybe the fanfic writer makes Red leave behind some sort of legacy or power that Ash unknowingly inherits. But this is all just speculation within the realm of fan - created stories and not based on the real Pokémon franchise.
There is no evidence at all. J.K. Rowling started writing Harry Potter on her own, with her own imagination. The series has a clear origin story, from her coming up with the idea of a boy wizard to building the entire wizarding world. Fanfiction usually builds on existing works, but Harry Potter is the original source, not the other way around, especially not related to something as unclear as 'belloch' fanfiction.
There could be various types of evidence. For instance, if the fanfiction delves into the history of magic, there might be a family tree or some ancient texts that imply Harry's connection to Morgana. Also, the way Harry's magic behaves differently from others could be a sign. Maybe his spells have an unusual tint or effect that is related to Morgana's magic. However, without actually reading the specific fanfiction, it's hard to say exactly what evidence it presents.
Well, in such fanfictions, it could be that the author invents new prophecies or backstories. They might say that there was a mix - up at the time of Harry's birth, and that he was actually Regulus's son all along. Or perhaps there are some items or memories that only make sense if Harry is related to Regulus, like a locket that has a special connection to both of them.
Often, fanfictions that claim Hermione is Voldemort's heir will create some convoluted backstory. For example, they might say that there was a secret affair between a distant relative of Hermione's and one of Voldemort's ancestors. This would then be used as the basis for her being his heir. However, this is pure invention for the sake of the fanfiction and has no basis in the real Harry Potter story. The original story has no such indication, but fanfiction allows for these wild and imaginative ideas to be explored.
In most fanfictions, the evidence is often fabricated within the fictional narrative created by the author. It could be things like hidden memories, secret meetings in the past that were never revealed in the original series, or some magical bond that was only known to a few. However, in the original 'Harry Potter' canon, there is no such relationship between Harry and Snape.
In most of the fanfiction exploring this concept, evidence is often fabricated within the alternate universe created by the author. It might be things like Snape secretly protecting Harry out of a fatherly love that is more intense than just a teacher - student bond. However, in the original 'Harry Potter' series, there is no such indication.