Perhaps Cersei's son, having grown up seeing the chaos his mother caused, could bring about a new form of governance. Instead of the feudal system that was prevalent, he could introduce a more democratic - like system where the voices of the lords and the common folk are heard. This would be a huge change from the power - hungry struggles that were characteristic of the Game of Thrones world.
He could influence events by being a voice of reason in Cersei's court. If he's intelligent and perceptive, he might be able to persuade his mother to make more diplomatic decisions rather than always resorting to force.
The son's character might develop as he uncovers family secrets. Knowing about his mother's true nature and his father's misdeeds could make him question his own identity. He could start as a naive young man, but as he digs deeper, he becomes more cynical. But instead of being consumed by it, he decides to break the cycle of corruption and lies that his family has been part of. He could start to develop his own moral code, different from the cut - throat ways of his parents.
In an interesting fanfiction plot, Cersei's son could be exiled from King's Landing. During his exile, he forms a band of outcasts. Together, they build a new community away from the power struggles of the capital. As he grows, he realizes that his mother's way of ruling is wrong. Eventually, he returns to King's Landing with his new - found wisdom and tries to overthrow his mother's tyrannical rule, not to take over but to establish a more democratic and fair system for the people of Westeros.
He might become more cynical. Growing up with Cersei as his mother, he would be exposed to a lot of political backstabbing and power - mongering. But his original Naruto - like optimism might still peek through at times. For example, he could initially be distrustful of people but then find a few he truly believes in and regain some of his more positive outlooks.
One of the main events was her rise to power. Cersei managed to take the throne after her son's death. She also had many conflicts with other powerful characters like Margaery Tyrell. For example, she plotted against Margaery which led to Margaery's downfall. Another significant event was her walk of atonement which was a very humiliating experience for her but also showed her resilience in a way as she was able to come back from that and continue her fight for power.
The Baratheon daughter might also be a catalyst for change in terms of the social norms of Westeros. If she advocates for the rights of women or the lower classes, she can start a movement. Imagine her using her position to speak out against the unfair treatment of smallfolk or the limitations placed on women in inheritance and leadership. This could lead to significant social unrest or reform, which would be a major shift in the story's direction.
In some fanfiction, Jaime's character might develop into a more remorseful figure. His relationship with Cersei could be a source of internal conflict, and he could start to question his loyalty to her more deeply, leading to a change in his actions and decisions.
Perhaps in the fanfiction, Cersei's son discovers a hidden power within himself. He uses this power not for domination like his mother would, but to heal the broken kingdom. He might travel across the land, learning from the common people and using his new - found abilities to bring prosperity.
The twin brother might befriend Tyrion. In the original story, Tyrion is constantly undermined by Joffrey. But the twin could see Tyrion's intelligence and value. Together, they could form a powerful alliance against Cersei and Joffrey. They could work towards a more just rule in King's Landing, reforming the laws and improving the lives of the common people. This would completely shift the power dynamics within the Lannister family and in King's Landing as a whole.
One possible plotline could be Cersei's son growing up to be a more benevolent ruler than his mother. He could see the destruction she has caused and try to make amends. Maybe he forms alliances with former enemies to bring peace to the Seven Kingdoms.