Well, in this fanfiction, it could start with Daphne being targeted by the Dementors for some specific reason. Maybe she has some information that the dark forces associated with the Dementors don't want her to spread. Harry, being the hero he is, just happens to be in the right place at the right time. He quickly conjures his Patronus, which is a stag, and it chases away the Dementors. Daphne is grateful and from that moment on, she becomes more involved in Harry's fight against the dark arts, and they form a strong alliance.
The main characters are obviously Harry and Daphne. Harry, the well - known hero from the Harry Potter series, is the one who does the saving. Daphne is the one in need of rescue from the Dementors.
Well, it could be that Daphne is in danger during a dark wizard attack at Hogwarts. Harry, being the hero he is, uses his skills and magic to fend off the attackers and save her. Maybe she was in the wrong place at the wrong time near the Forbidden Forest.
It could be that Daphne has a personal connection to Harry that she's not aware of until she starts investigating the strange magical disturbances around the Dursleys' place. Once she realizes it's Harry in trouble, she enlists the help of her friends or some sympathetic wizards to break Harry free. She might also face some challenges along the way, like dealing with the Dursleys' resistance or the Ministry of Magic's rules about interfering in Muggle affairs.
Well, perhaps there is some sort of magical accident at the World Cup. A spell goes wrong and endangers Daphne. Harry, being the hero he is, senses the danger and manages to counter the spell just in time. He might use his knowledge of defensive magic, which he has learned from his years at Hogwarts, to keep Daphne safe from the harmful effects of the misfired spell.
One possible plot could be that Harry discovers some new evidence that proves Draco's innocence. Maybe there was a frame - up by some dark forces within the wizarding world. Harry, being the hero he is, feels compelled to act and uses his influence and skills to break Draco out of Azkaban. This could lead to them having to go on the run together, hiding from the authorities while they try to expose the real culprits.
Well, it could start with Hermione showing signs of distress. Harry notices and starts to investigate. He finds out that there's a group of Slytherins who are using dark magic to mentally abuse Hermione, making her doubt her own abilities. Harry then challenges them to a wizard's duel and wins, forcing them to stop their abuse.
One possible plot could be a story where a character, perhaps Harry himself, is being haunted by Dementors more than usual. The lemon element could come in as a new form of magic or charm that has an unexpected side - effect related to love or attraction. Maybe a female character uses this new charm to fight off the Dementors' influence on Harry, and during this process, a romantic and somewhat steamy relationship develops between them.
Well, I'm not sure about specific 'Daphne saves Harry from the Dursleys' fanfiction titles off the top of my head. But you could also try Fanfiction.net. Browse through the Harry Potter section and look for tags related to Daphne and Harry's rescue from the Dursleys. It might take a bit of time, but you're likely to find some great reads there.
The plot could start with rumors reaching Harry that Draco is being unjustly treated in Azkaban. Harry, being the hero he is, decides to investigate. He uncovers a conspiracy within the Ministry of Magic that is trying to keep Draco locked up for political reasons. Harry then uses his connections, like his friendship with Neville who now has some influence in the Ministry, to get a hearing for Draco. During the hearing, Harry presents the evidence he has found, which includes magical artifacts that prove Draco's innocence, and Draco is finally released.
One possible plot could be that Harry, through some sort of magical accident or spell gone wrong, is turned into Daphne. He then has to navigate the world as a female Slytherin. He might struggle with the different social dynamics in Slytherin house compared to Gryffindor. And he has to keep his true identity a secret while trying to find a way to reverse the transformation. All the while, he could be learning things about Daphne's character and past that he never knew before.