There are several themes. Forgiveness is a big one. Harry has to forgive Severus for his past actions, and Severus has to forgive himself. The theme of trust also runs through these stories. Since they didn't trust each other much in the original, building that trust in the context of a rescue and romance is important. And of course, the power of love. It's shown as something that can overcome the animosity and difficulties they faced in the past, changing their fates and the way they view each other.
One common theme is redemption. Severus, who had a somewhat villainous image in parts of the original story, gets a chance to redeem himself through rescuing Harry and then developing a romantic relationship. Another theme is the breaking of barriers. They come from different backgrounds and have had a strained relationship in the original, so in these fan fictions, they break those barriers of enmity and class differences. Also, the theme of self - discovery often appears as they both learn more about themselves through this new relationship.
It has a certain following. Fans are drawn to the idea because it combines two very different characters. Severus is a brooding and complex figure, while Harry is the hero. When Severus rescues Harry, it can lead to a deep emotional connection that fans like to explore in a romantic context. It also allows for a re - imagining of the story's power dynamics and emotional arcs.
Perhaps Severus, while rescuing Harry, stumbles upon a hidden connection between the Dursleys and the Death Eaters. This would add a whole new layer of danger and mystery. He might have to fight off some of his former allies to get Harry to safety. It could also lead to a change in Severus' perception of Harry as he realizes the boy has been in more danger all along than just from Voldemort.
One common theme is redemption. Severus, who has had a complex and often negative relationship with Harry in the original series, gets a chance to redeem himself by protecting and caring for Harry. It shows that he can be more than just the strict and often cruel teacher.
His character could also develop in terms of loyalty. At first, he might be rescuing Harry for some self - serving reasons, like to gain favor with Dumbledore or to stop a threat to the wizarding world that he discovers is related to the Dursleys. But as he spends time with Harry, he could develop a genuine loyalty towards the boy, which is a big shift from his previous animosity.
One common theme is redemption. Snape, who has had a rather dark past in the original series, through rescuing Harry, finds a path to redemption and love. Another theme is the breaking of barriers. They come from different generations and have had a somewhat antagonistic relationship in the books, but in the fanfiction, the rescue event allows them to break those barriers and form a romantic bond.
One common theme is redemption. Snape's actions to save Harry are often seen as a way for him to atone for his past mistakes or his association with the Death Eaters. It gives him a chance to be a hero in his own right.
One common theme is the idea of overcoming differences. Since they may be from different backgrounds or houses in the wizarding world, the fan fictions often focus on how they bridge those gaps. For example, in many stories, Harry's Gryffindor bravery and Theodore's more reserved nature from his own house are things they have to work through.
Love against all odds is also a frequent theme. There are often external forces like dark magic, or the disapproval of the wizarding community that try to keep Harry and the creature apart. But their love prevails, showing the power of love in a rather fantastical setting. This makes the stories very engaging and full of emotional highs and lows.
In the 'Charlie rescues Harry from Ron romance fan fiction', it could be that Ron's romantic advances towards Harry are making Harry feel trapped. Charlie, who has a good understanding of both of them, might use his charm and knowledge of the wizarding world to create a distraction. He could introduce Harry to some new magical creatures or ancient spells, thus rescuing Harry from the awkwardness of Ron's romance.
Writing or discussing sex - related fan fiction is inappropriate and goes against ethical and moral standards, so I cannot provide relevant content.