In the fanfic, she might be used as a bargaining chip. The Boltons could try to trade her for some advantage, like territory or loyalty from other houses.
In a fanfic where Arya gets captured, she might be used as a bargaining chip. Her captors could try to exchange her for something valuable, like a strategic location or a large sum of gold. Maybe they want to use her to manipulate the Starks.
Another idea for a fanfic is that Arya discovers she's not really the last Stark. There could be a long - lost relative hidden away. She then embarks on a journey to find this person. Along the way, she has to overcome many obstacles and face new enemies, all while trying to keep the hope of the Stark family alive.
Well, a plot could be centered around a political intrigue where Ramsay believes Arya is a valuable pawn in his power - grabbing scheme. But Arya, being Arya, has her own agenda. She could start building her own network within Ramsay's territory, befriending the downtrodden and oppressed. Eventually, she could lead a rebellion from within, using the element of surprise and her knowledge of Ramsay's weaknesses.
Well, they could reunite in a moment of great danger. Maybe the White Walkers are attacking again, or there's a new enemy threatening their homeland. Their reunion would then be filled with urgency as they quickly strategize on how to defend their people. Arya might use her stealth skills, and Jon his leadership, to face the threat side by side.
In this fanfic, Naruto might be tortured for information about the Hidden Leaf. The Akatsuki are known for their ruthless ways, so they could use various jutsu to make him talk.
She could use her skills as a Faceless Man. Arya might disguise herself as someone else and slip away unnoticed.
Arya might use her pregnancy as a form of strength. Instead of seeing it as a weakness, she could turn it into a motivation to create a better world for her child. She could start training a new generation of fighters, including her unborn child in her plans for a more just and peaceful Westeros.
In a 'naruto gets captured' fanfiction, he might be tortured for information. His captors could be after the secrets of his Nine - Tails chakra. They may try to use him as a bargaining chip against Konoha.
Well, in this fanfiction, perhaps Steven could be held captive by an old enemy. Maybe he'll have to use his wits to escape, like finding a weakness in the prison's security system.
Well, perhaps Gengar is captured by a powerful trainer. The trainer might use a special Poké Ball to catch it. Then, Gengar could try to escape from the ball by using its ghostly powers.