The fanfic could be set in a post - apocalyptic world. Scott, Alex, Gabriel and the OC as the fourth brother are trying to survive. They have to find food, shelter and avoid the various gangs that roam the land. Scott is the one who often scouts for new areas, Alex figures out how to make the best use of the resources they find, Gabriel is in charge of security, and the OC as the fourth brother has a special ability to sense danger from afar. Their bond as brothers helps them stay alive in this harsh world.
Perhaps in the fanfic, they are all students at a prestigious academy. There are different houses at the academy and they are from the same house. They enter a competition against the other houses. Scott is determined to win for their house's pride, Alex studies hard to master the academic aspects of the competition, Gabriel trains physically for the sports part of it, and the OC as the fourth brother has an unexpected talent that gives their house an advantage. Along the way, they deal with rivalries, make new friends, and of course, strengthen their brotherly relationship.
A simple plot could be that they are all part of a guild in a fantasy world. The guild is facing a rival guild that is causing trouble. Scott, Alex, Gabriel and the OC as the fourth brother have to work together to defend their guild's honor. They train hard, with Scott being the most enthusiastic about combat training, Alex focusing on the strategic aspects, Gabriel on physical strength improvement, and the OC using his unique skills (maybe some form of magic) to give them an edge.
In this fanfic, the relationship between Scott, Alex, Gabriel and the OC as the fourth brother could be explored in depth. It might start with the OC being an outsider, not fully accepted by the others at first. But as time goes on, through shared experiences like defending their village from invaders, they come to realize his value and he becomes an integral part of their brotherly bond. Their individual personalities would also play a role in how they interact. For example, Scott's impulsiveness might sometimes clash with Alex's more cautious nature, while Gabriel tries to keep the peace, and the OC brings a fresh perspective to their group dynamics.
When writing, focus on the relationships between the characters. For instance, show how the OC's older half - brother interacts with Scott. Are they friends or rivals? You can also include some dialogue to make the story more engaging. For example, Gabriel could say something funny to break the ice when there is tension between the characters. Also, describe the settings vividly so that the readers can picture the story in their minds.
There might be a fanfic where the relationships between them are explored. For example, the OC's older half - brother could have a conflict with Scott at first because they have different views on how to handle a certain situation. But as the story progresses, they learn to understand each other. Alex and Gabriel could be the mediators in this situation, trying to keep the peace between the two.
In the fanfic, their older brother might be a bit of a rebel. He could have left the X - Men for a while due to some ideological differences. But then, when Scott and Alex find themselves in a really tough situation, he comes back to help. He brings with him some new fighting techniques he learned during his time away, and together they form a stronger team.
Scott could be the leader - like figure among them, using his optic blasts to protect his brothers and the X - Men. Alex, with his powerful energy blasts, might be the more impulsive one who often rushes into danger. Their older brother could be the strategist, coming up with plans to outwit the enemies.
One common theme is brotherhood. Given their relation, many fanfics explore how their bond as brothers is strengthened or tested in different situations within the X - Men world.
Well, here's a plot idea. The male OC has a special connection to a magical artifact that is coveted by an evil force. He has to protect it while also trying to figure out why he has this connection. Also, he could be in a love triangle with two other characters in the guild, which adds a lot of drama to the story. Another idea is that he's the key to unlocking a hidden power within the Fairytail guild, but he doesn't know it at first and has to go through a series of trials to discover his true potential.
In some fanfics, Big Brother Gabriel is given a backstory that makes him more relatable. For example, he might have had a difficult time growing up in the celestial realm, facing certain challenges that shaped his personality. This could lead to different interactions with characters like Aziraphale and Crowley. He might be more sympathetic towards their relationship, or he could be even more determined to stop it depending on how the author wants to spin the story.
One possible plot could be that the OC is a new mutant who arrives at the X - Men school. Jean Grey senses a powerful and unique energy within the OC. Scott is initially cautious but as they all train together, the OC starts to develop feelings for both Jean and Scott. Meanwhile, a common enemy emerges that forces them to work closely, and during this time, a complex love triangle forms as Jean and Scott also find themselves drawn to the OC in different ways.
One plot idea could be that the male OC is a new student at Constance Billard. He quickly becomes the talk of the school because he has a mysterious past. Maybe he's secretly a millionaire's son who has been kept out of the public eye until now. He starts to date one of the popular girls, but this causes jealousy among the other guys at school, leading to all kinds of drama.