Yes, there might be. The 'Korra' and 'Asami' pairing is quite popular in the fan community, and it's not uncommon for fans to create fanfiction exploring different scenarios like this. However, the availability and content can vary greatly depending on the platforms where fanfictions are hosted.
If we follow the more traditional route, Mako could be the father. They had a relationship in the show, and it would be a natural progression for them to start a family. Their relationship had its ups and downs, and the pregnancy could be a new chapter in their story together.
Well, one possible plot could be that Korra and Asami decide to start a family together in a modern AU. They face challenges like how to balance their important work with raising a child. Maybe Korra has to deal with her bending powers during pregnancy, like how to control them without endangering the baby.
In many fanfictions where Gil gets kidnapped, it could be for various reasons. Maybe it's by a rival group who wants to use him as a bargaining chip against his friends. For example, in some stories, Uma's crew might be targeted because they are seen as a threat in the Isle of the Lost. Gil, being a part of that crew, gets kidnapped. Writers often use this plot device to create drama and show the loyalty and courage of the other characters as they try to rescue him.
In a Korra Gets Asami Pregnant Fanfiction, the plot might begin with Korra and Asami already in a loving and stable relationship. Asami discovers she's pregnant, which is a huge surprise. The story could then revolve around how Korra, being the strong - willed and protective partner, tries to ensure Asami has a smooth pregnancy. There could be elements of Korra using her bending abilities to help Asami in some way, like creating a comfortable environment for her. Also, the fanfiction could explore how their friends from the series react to the news, some being overjoyed and others maybe a bit worried. It could also touch on how they plan to raise the child in a world that is still recovering from the events of the original series.
One idea could be that Sam is kidnapped by a group of rogue hunters who think he's gone too far in his use of demon powers. They lock him in an abandoned bunker and try to 'exorcise' the 'demon' out of him, not realizing he's in control. His brother Dean has to race against time to find him, following a series of cryptic clues left by the kidnappers.
Natsu was walking through the forest one day when suddenly a group of dark mages emerged from the shadows. They quickly overpowered him with some sort of magic -binding spell. They dragged him away to an old, creepy lair. His friends back at the guild soon realized he was missing and set out on a search mission. Happy flew around frantically looking for any sign of his friend. Lucy, Gray and Erza teamed up and followed some leads they found in the forest. They were determined to rescue Natsu no matter what it took.
Peter's kidnapping was a carefully planned event. The kidnappers had been observing him for weeks. One day, as he entered a park, they grabbed him. They blindfolded him and took him to a secluded location. Peter was scared but he didn't show it. He started to befriend one of the kidnappers, a young guy who seemed a bit hesitant about the whole thing. Peter told him stories about his life and gradually the kidnapper started to have second thoughts. Eventually, the kidnapper helped Peter escape by distracting the others.
It could be a new character created specifically for the fanfiction. Maybe a young scientist who is working on a project related to the super - soldier serum. Since Bucky has a history with the serum, this would create an interesting dynamic.