There are some fanfictions that explore a romantic relationship between Black Widow and Black Panther. However, this often takes a lot of creativity as they come from different parts of the Marvel universe. For example, a story might have them meet during an Avengers - related event and gradually develop feelings for each other over the course of several adventures together.
A theme that has been growing in popularity is redemption. Suppose Black Widow has a past mistake or Black Panther faces a situation where he needs to make amends. Fanfiction writers might create a scenario where they help each other find redemption. It could be something like Black Widow helping Black Panther deal with a political fallout in Wakanda due to a decision he made, or Black Panther guiding Black Widow to atone for something she did during her time in the Red Room.
One interesting storyline could be a mission where Black Panther and Black Widow have to team up to take down a powerful international arms dealer. They could combine their unique skills, with Black Panther's enhanced strength and agility from the heart - shaped herb and Black Widow's spy training and combat expertise. Another could be a story set in Wakanda where Black Widow is sent on a diplomatic mission and she and Black Panther develop a mutual respect and friendship as they deal with political intrigue within Wakanda and threats from outside forces.
A frequent theme might be the idea of two strong, independent characters coming together. Both Black Panther and Black Widow are powerful in their own right. In fanfiction, they might learn from each other's strengths and overcome their individual weaknesses while falling in love. Also, themes of trust and betrayal could be explored, considering Black Widow's history as a spy.
Yes, there might be some out there. You can start by looking on fanfiction websites like Archive of Our Own. However, keep in mind that such crossovers are quite creative and might not follow the official Marvel storylines very strictly.
Well, Black Panther has a strong connection to his heritage and the spiritual side of Wakanda. In a fanfiction, this could mean that when he and Black Widow are on a mission in a haunted or magically influenced area, he can use his knowledge of Wakandan spiritual practices to get them through. Black Widow's experience in espionage means she has a wide network of contacts all over the world. She could use these to help Black Panther when he needs information about a particular international criminal or situation outside of Wakanda. Their different backgrounds can create a great dynamic of learning from each other in a story.
The Black Panther comic has its own unique fictional universe and narrative that is not related to the Black Panther Group. The comic's creation was based on comic book concepts and storytelling rather than any direct connection to the group.
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.