There's a 'Harry meets other Potters' fanfic where they meet in a time - traveling scenario. Harry from different points in time comes together. It's really cool as they compare their different experiences at Hogwarts, like how magic was taught differently in their respective times, and they also exchange spells and magical knowledge.
You can try looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions, and you can search for 'Harry meets other Potters' specifically. There are also tags and filters you can use to narrow down your search to the exact type of story you're interested in.
Well, it could be a story where Harry stumbles upon the second branch of the Potters. Maybe it's a long - lost part of the family that has some unique magical abilities or secrets. Since it's a fanfic, the author might take creative liberties and introduce some interesting plot twists, like the second branch being involved in a hidden magical society or having a connection to an ancient prophecy that Harry then gets drawn into.
Harry Potter is a given as the main character. In terms of the second branch of the Potters, it could include a variety of characters. There might be a Potter who has been living outside of the main wizarding society and has developed some unique magical skills. There could also be a group of Potters, like siblings or cousins from the second branch. One of them might be a bit of a rebel and another a more traditional Potter. These characters would interact with Harry, and their different personalities and abilities would drive the story forward.
Perhaps there's a plot against Harry by some dark forces, and the Potters believe that only they can protect him properly. They might think that the people who have been taking care of Harry so far are not equipped to handle the new and more dangerous threats. Also, it could be that the afterlife in the wizarding world has some rules or opportunities that allow them to try and get Harry back into their family fold. They could have been given a second chance, so to speak, and are eager to take it.
Sure. 'Lily's Surprise Meeting with the Potters' is quite good. It's a short and sweet fanfiction that focuses on the initial shock and excitement when Lily meets the Potters.
Yes, they might. Just like any other group of people, those who identify as Blacks or are part of the Potter family name (if we assume there are real people with that name) could be fans of the Harry Potter series and thus read fanfiction. Fanfiction offers a wide range of interpretations and extensions of the original story, and anyone with an interest in the magical world of Harry Potter could be drawn to it.
One possible motive could be that the Potters discovered some dark plot by the Malfoys involving Harry. Maybe they found out that the Malfoys were planning to indoctrinate Harry into their pure - blood supremacist ideology against his will. So, to protect Harry from that, they kidnapped him.
Sirius Black could also be part of it. He was Harry's godfather. He might have escaped from Azkaban earlier in this fanfic. He teams up with the Potters to rescue Harry. He could be the one who scouts out the Dursleys' house before the actual rescue operation, using his skills as an Animagus to stay hidden.
It could also be that the Potters are under some sort of magical influence or curse. In the fan fiction world, there could be a dark force at play that makes them see the twins as more important. This force might be manipulating their emotions and perception, leading to the neglect of Harry.