There could be a really interesting fanfic where a Dragonborn enters the world of Game of Thrones during Joffrey's reign. Maybe the Dragonborn would initially be seen as a threat by Joffrey. But the Dragonborn's powers could change the power dynamics in King's Landing. For example, if the Dragonborn has the ability to control dragons, it would be a huge advantage over the Lannisters who rely mainly on their wealth and military might at that time.
In the context of the fanfic, the Dragonborn's presence could also expose Joffrey's weaknesses more clearly. The people of Westeros, seeing someone with such great power (the Dragonborn) who is not as cruel as Joffrey, might be more inspired to rise up against Joffrey. And Joffrey's own allies might start to question their loyalty to him when they see the Dragonborn as a potential new power player in the game of thrones.
There are some really interesting fanfics out there that combine the concepts of a Dragonborn in the Game of Thrones universe with Joffrey. One I've read had the Dragonborn as a sort of mysterious figure who arrives in King's Landing during Joffrey's reign. The Dragonborn's presence throws the power dynamics into chaos as they have their own set of powers and motives. It was really fascinating to see how the author played with the different personalities and politics of the Game of Thrones world in that fanfic.
In the official 'Game of Thrones' series, it was Sansa's necklace (which was actually a poisoned device) that led to Joffrey's death, not Arya. However, in some fanfics, authors might create alternate storylines where Arya kills Joffrey. But these are non - canonical and just creative interpretations by fans.
If the Dragonborn met Joffrey in a fanfic, it would be a clash of two very different characters. Joffrey is cruel and power - hungry, while the Dragonborn has their own sense of justice and power from dragon - related abilities. The Dragonborn might see Joffrey as a tyrant and try to oppose him. Maybe the Dragonborn would use their dragon - riding skills to intimidate Joffrey or his court.
Some fanfictions might focus on an alternate universe where Joffrey is not a king. He could be a simple knight, and the story could explore how his personality would develop without the power and privilege of the throne. He might learn humility and honor in a different way.
One interesting scenario could be a rewrite of their relationship where Joffrey is secretly influenced by a more benevolent force. This might lead him to treat Sansa with more kindness than in the original series. Maybe he starts to see the value in having an ally in Sansa rather than just using her as a pawn.
In many fanfictions, secondary characters around Sansa and Joffrey are well - written. For instance, Tyrion. His relationship with both Sansa and Joffrey in the original series was complex. In fanfiction, his character can be used to further the plot involving Sansa and Joffrey. He might be the voice of reason or a catalyst for change in their relationship.
There would be chaos. Joffrey is a king, so his death would create a power vacuum. His mother Cersei would be furious and would likely start a manhunt for Arya. The Lannisters might declare war on Arya's family or allies. The political landscape would be completely disrupted as different factions would try to take advantage of the situation.