In a 'negima meets black panther fanfiction' plotline, the magical artifacts in Negima could be of great interest to the people of Wakanda. They might want to study them for their own technological advancements. On the other hand, the Black Panther's suit and its abilities could be something that the Negima characters are in awe of or try to replicate. There could also be a plot where a character from Negima, like Negi, tries to learn from T'Challa about leadership and in turn teaches him about magic, leading to a mutual exchange of knowledge and a unique friendship.
I'm not sure about specific 'negima meets black panther fanfiction' stories off the top of my head. You could try searching on popular fanfiction websites like Archive of Our Own or FanFiction.net. There might be some really creative crossovers there.
One possible plotline could be a power - exchange. Naruto learns about the power of Vibranium from Black Panther and tries to incorporate it into his ninja tools. Meanwhile, Black Panther gets interested in chakra and starts training to use it.
Perhaps in this fanfiction, the magic of the Harry Potter universe and the technology/vibranium of Wakanda are somehow intertwined. For example, the Deathly Hallows could have a connection to Wakandan artifacts. Harry could find himself in Wakanda and be mistaken for a threat at first. But as he proves his good intentions, he and Black Panther could start to exchange knowledge. They could then use their combined powers and knowledge to stop a dark force that is trying to steal Wakandan resources and use them to gain power over the wizarding world.
One possible plotline could be that Izuku is somehow transported to Black Widow's universe. There, he has to adapt to a world without quirks and learn to use more traditional combat methods.
One possible plotline could be Tony as a panther facing off against some kind of threat to his territory. Maybe there are other supernatural creatures trying to encroach on his space.
One possible plotline could be that Casetopia Black is a powerful wizard from a far - off land. He arrives at Hogwarts and challenges Harry Potter to a magical duel to prove his worth. This duel could lead to a new friendship or rivalry between them.
Well, in this fanfiction, there could be some really cool battles. Maybe Negi from Negima could use his magic against the Avengers' superpowers. For example, his lightning magic against Thor's thunder powers. It would be an interesting clash of different power systems.
There could also be a plotline where there is some sort of danger threatening the Pride Lands. Kovu and Mufasa, despite their differences, team up to face this threat. Kovu brings his unique skills and knowledge from his pride, and Mufasa uses his wisdom and leadership. As they work together, they develop a mutual respect for each other that was not there before.
Maybe Talion could help Frodo on his journey to destroy the One Ring. He has his own combat skills, so he could offer protection against the various threats that Frodo faces.
One possible plotline could be a competition between Naruto and Sebastian. For example, a contest of skills where Naruto shows off his ninja moves and Sebastian displays his butler feats.