One great piece could be 'The Magical Meeting' where the female Harry Potter enters the Marvel universe and meets Bruce Banner. Their encounter leads to an interesting exploration of different magic systems and scientific knowledge.
There's a fanfic where Bruce Banner is a visiting scientist at Hogwarts. In the story, his scientific knowledge clashes and also meshes with the magic of the wizarding world. It shows how the two different forms of knowledge, Muggle science and magic, can interact. This 'Harry Potter Bruce Banner fanfic' is really thought - provoking and gives a fresh take on both universes.
Identity is also a common theme. Harry Potter has her identity as a wizard, a Gryffindor, and someone who has defeated Voldemort. Bruce Banner has his identity as a scientist and the Hulk. In these fanfictions, they may struggle with their identities, especially when they are in a new world or situation together. They might question who they are and how their identities change when they are with each other.
In fanfiction, Bruce Banner could save Harry Potter through his scientific knowledge as well as the Hulk's powers. Maybe there's a situation where a magical curse is spreading uncontrollably. Bruce, in his normal state, could analyze the curse using his scientific expertise and figure out a way to stop it. And if there are any physical manifestations of the curse that need to be dealt with, the Hulk could step in and use his strength to destroy or contain them. This would show a great combination of the scientific and magical elements in the story.
I really liked a fanfic where fem Harry Potter accidentally travels to Bruce Banner's world. It shows how she tries to adapt to this new world full of science and technology, which is so different from the magical world she's used to. And Bruce Banner is intrigued by her magic. It's a great exploration of two very different characters coming together.
I'm not sure specifically about 'Bruce Banner x Harry Potter' yaoi fanfiction. Yaoi fanfiction often involves creating romantic or sexual relationships between male characters in a non - canonical way. However, it might be a very niche combination and not as common as some other fanfiction pairings. You could try searching on some dedicated fanfiction websites like Archive of Our Own (AO3) to see if there are any works of this kind.
One interesting concept could be a crossover where the magic of the Harry Potter world interacts with Bruce Banner's scientific knowledge. Maybe Banner could be intrigued by the potions in the wizarding world and try to analyze them with his scientific mind. Another concept might be a situation where the Hulk's strength is pitted against the powerful magic spells of Harry Potter characters.
There's also 'The Unexpected Bond'. It focuses on the unique relationship between Bruce Banner and an OC. It shows how their different personalities complement each other. The author does a wonderful job of creating a believable and engaging story.
One great Bruce Banner x Reader fanfiction is 'A Different Kind of Strength'. It shows a really interesting relationship between the reader and Bruce. The way the author portrays Bruce's inner struggle and how the reader helps him through it is quite engaging.
The fanfiction 'Banner and Romanoff: Unlikely Allies' is also quite good. It starts with their professional relationship in the Avengers and then slowly evolves into something more. It has some really interesting character interactions and a well - paced plot that keeps you engaged.
First, you need to decide on the basic plot. Will it be a story where they meet in one of their worlds, or will it be a new world entirely? Then, think about how their personalities will interact. Bruce is a brilliant scientist with a temper problem, while Harry is a brave and determined wizard. You can create interesting scenes based on their different skills and mindsets. For instance, Bruce could use his scientific knowledge to analyze a magical phenomenon, and Harry could use magic to protect Bruce from danger.