In MLP fanfiction, male changeling drones can be portrayed in various ways. Some might be shown as loyal servants to the Queen, while others could be rebels. They often have the ability to shapeshift, which can add an interesting dynamic to the stories. For example, a male drone could befriend a pony and use his shapeshifting to protect them from danger.
There are often changeling fanfictions that focus on their relationships with other species. Like a story about a changeling forming an unlikely friendship with a brave knight. In these stories, the author might play with the idea of trust and deception which are central to the concept of changelings.
I'm not sure if it's a popular concept. It might be a niche idea within the vast Harry Potter fanfiction community. There are so many different types of fanfictions out there that it's hard to say whether this one in particular has gained widespread popularity.
One common theme is redemption. Since changelings are often seen as the antagonists in the original My Little Pony series, many fanfictions focus on them finding a new way and redeeming themselves. For example, a changeling might decide to stop using their shape - shifting abilities for deceit and instead use them for good.
Sometimes, an antagonist in the fanfiction, like a hunter who is out to expose or harm the changelings, can be a popular character as well. Their conflict with the main characters creates tension and excitement in the story.
Well, it could be about many things. It might focus on the changelings in the My Little Pony universe and how they are experiencing the changing times. Maybe it shows their struggle to adapt, or their new roles in a changing world within the MLP setting.
A 'changeling novel' is centered around the concept of a changeling. Changelings are often part of fairy tales and superstitions. In these novels, you can expect to find themes like identity confusion, as the changeling may not be aware of its true nature. There may also be themes of loss and longing, as the family of the replaced human child mourns their real child. The plot could involve attempts to reverse the changeling situation or to come to terms with it.