Perhaps the fanfic could be set in a post - Endgame world. Black Widow is somehow brought back and she teams up with Okoye to retrieve a powerful artifact that has fallen into the wrong hands. They travel across different realms, facing various enemies. Their different personalities, Black Widow's more sardonic and independent nature and Okoye's loyalty and discipline, would lead to some great character interactions.
They could start with a bit of a rivalry. Okoye might see Black Widow as an outsider and be a bit suspicious of her methods. Black Widow, on the other hand, might find Okoye's strict adherence to Wakandan traditions a bit stifling at first. But as they face challenges together, they start to respect each other. For example, when in a fight, Black Widow might be impressed by Okoye's use of the spear and Okoye could admire Black Widow's agility.
The plot could start with Batman investigating some strange activities in Gotham that are linked to a Russian spy ring. This leads him to cross paths with Black Widow who is on a mission for S.H.I.E.L.D. They initially misunderstand each other's motives and end up in a fight. As the story progresses, they realize they are both after a common enemy and team up.
In a fanfic scenario, Batman might have the edge. He's a highly trained martial artist with a vast array of gadgets. His detective skills could also give him an advantage in predicting Black Widow's moves. However, Black Widow is no slouch. She has extensive combat training and experience in espionage. It could be a very close fight depending on the circumstances written in the fanfic.
Natasha Romanoff, the Black Widow, hails from a dark past. She was orphaned during World War II and then taken in by the Soviets. In the Red Room, she endured rigorous training, both physical and mental. This training made her an expert in combat, espionage, and deception. Her skills are on par with some of the mightiest superheroes in the Marvel Cinematic Universe. For example, she can hold her own against the likes of Hawkeye and even Captain America in combat situations. Her origin story is a crucial part of understanding her character's motives and actions throughout the Marvel stories.
Often, characters like Hawkeye might be paired with her. Their long - standing friendship in the original Marvel universe could translate into an interesting dynamic in the fanfiction. He could be someone who helps her adjust to her new form, or they could go on adventures together with her new - found size being an advantage.
Definitely not real. Black Widow is a fictional superhero character whose adventures and storyline are crafted within the realm of fiction and fantasy for fans to enjoy.