Perhaps Evie Nightshade is a descendant of a dark wizard or witch. The 'Darkness' in the title could refer to an ancient power or curse that she discovers she has inherited. The plot might involve her struggling to control this power while also trying to fit in at Hogwarts. She could face prejudice from some students who sense her connection to the Darkness, and she has to find allies among the Hogwarts community to help her deal with this newfound aspect of herself.
I'm not sure specifically about a 'Evie Nightshade Darkness' in Harry Potter fanfic. You could try searching on major fanfic websites like Fanfiction.net or Archive of Our Own. They have a vast collection of Harry Potter fanfics and you might find something related there.
One possible plot could be that Harry, after facing a great personal loss or a moral dilemma, briefly succumbs to the dark side. He might start using dark magic in secret. However, through the love and support of his friends like Hermione and Ron, he realizes the error of his ways. They remind him of the values he once held dear, and slowly he battles his inner demons and emerges from the darkness, stronger and more determined to fight against Voldemort and true evil.
It could be about Zoe Nightshade somehow getting involved in the wizarding world of Harry Potter. Maybe she has some special powers that are useful in the fight against Voldemort. For example, her skills with plants could be used to create powerful potions or defenses.
I'm not sure specifically as there are many different fanfics with that title. It could involve new adventures of Harry Potter in a world filled with the struggle between lightning (maybe representing some form of magic or power) and darkness (perhaps dark magic or evil forces).
One possible plot could be that Harry Potter, through some magical mishap or powerful spell, is transformed into a bride. Maybe he has to go on a quest to find a way to reverse the spell while dealing with the strange reactions of his friends and the wizarding world. For example, Ron might be completely confused and Hermione would be trying to find a solution in the library.
The plot might center around Harry being the master of darkness as a way to subvert the prophecy. Instead of being the 'Chosen One' in the typical light - against - dark way, he uses the knowledge of the dark arts to understand and outwit Voldemort. He could be learning long - forgotten spells from the darkest corners of Hogwarts library and using them to his advantage.
Maybe it could be about a character, perhaps Harry himself, being corrupted and turning into a 'Prince of Darkness'. He could start using dark magic and turn against his friends and Hogwarts.
One possible plot could be that Zoe Nightshade is a new character who comes to the Naruto world from another dimension. Naruto meets her and at first is suspicious, but then they realize they both have a common goal of protecting their respective worlds from a new, powerful enemy. So they team up and use their unique abilities to fight the foe.
Perhaps there's a prophecy in both universes that foretells of a coming disaster that can only be averted by the combined forces of the wizarding world and Riddick. Riddick is drawn to the wizarding world because of some strange magic that he senses. Once there, he meets Harry Potter. At first, they don't trust each other. But as they face challenges together, like strange magical - mechanical hybrids created by a rogue wizard who has been experimenting with technology from Riddick's world, they start to respect and rely on each other, ultimately working together to save both universes.
One possible plot could be that some Hogwarts students go on an exchange program to a magical ranch in the American West. There, they meet cowgirls who are also witches. Together, they face a new dark magic threat that is affecting the ranch's magic. The transformation (TF) aspect could be that the Hogwarts students learn new spells from the cowgirls that transform the local magical creatures in unexpected ways.