Black Noir is black in the comics. The creators have designed the character in such a way to give a specific look and feel, and the black complexion is an integral part of that design.
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 Legend of Black Panther is an audio novel that can be listened to for free. However, the search results did not provide clear information on which platform could be listened to for free. Therefore, I don't know the specific platform for free listening to books.
The plot could start with some sort of interdimensional rift that brings Gregor Clegane to Wakanda. Black Panther, seeing this strange and brutish intruder, decides to confront him. At first, Gregor might seem to have the upper hand due to his size and brute strength. But as the battle progresses, Black Panther figures out his opponent's fighting style and starts using his technology, like the energy daggers and his suit's abilities, to gain the advantage. Eventually, Black Panther manages to defeat Gregor and figures out a way to send him back to his own world.
It's very important as it gives the backstory. It shows how the Black Panther character and the Wakandan nation came to be. It sets the foundation for the character's values, powers, and the unique culture of Wakanda.
One great 'Black Panther' fanfiction is 'The New Wakanda' which explores a Wakanda that has to face a new, unseen threat. It has great character development for T'Challa and his sister Shuri.