Tony Stark in a Star Wars fanfic might be a sort of outsider who brings new ideas. He could team up with some of the Jedi or the Rebels. He'd probably be really interested in the Force, trying to understand it from a scientific perspective. And he'd surely use his engineering skills to upgrade starships or build new defense systems for the good guys.
One great fanfic could be about Arya Stark rebuilding Winterfell as the last Stark. It might explore how she uses her skills she learned during her travels to bring back the glory of her family's home. She could train new guards, establish trade routes, and make Winterfell a stronghold again.
In some fanfics, Arya Stark might be presented as the last Stark, but it really depends on the specific plot and direction the fanfic author takes. There could be plot twists where other Starks are revealed to still be alive.
It could be a bastard child of a Stark that was kept hidden for some reason. Maybe for fear of political ramifications or because of some dark family secret.
Common themes include the bond of family, which is shown through their daily interactions, like Tony reading bedtime stories to Morgan. The theme of mentorship also pops up, as Tony imparts his knowledge and skills to Morgan. Additionally, there is often the theme of loss and remembrance, as in how Morgan copes with the loss of her father and how she keeps his memory alive in different ways in the fanfics.
It could be really interesting. Maybe Tony Stark would try to build his own lightsaber using his high - tech knowledge. He might be impressed by the Force and try to find a scientific explanation for it. He could also end up in a Star Wars universe and use his Iron Man suit to fight alongside the Jedi or the Rebels.
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.
He could fit in as an inventor. He'd use his skills to create new weapons or tools for the Star Wars characters. For example, he could make a better targeting system for the X - wings.