One cool Dark OC is Selene Darkthorne. She's a transfer student from a foreign wizarding school where the study of Dark Arts was more accepted. At Hogwarts, she stands out because of her different approach to magic. She has a bit of a mysterious air about her and is often involved in plots that involve ancient Dark magic artifacts. There's also Adrian Shadowbrook. He's an OC who was cursed by a Dark wizard, which made him have an affinity for the Dark Arts against his will. He spends a lot of his time trying to break the curse and find his true self.
There's a character named Lyra Blackwood in some fanfictions. She's a Dark OC who was born into a family with a history of Dark Arts practice. But she has a conscience and struggles between following her family's traditions and doing what she believes is right. Another interesting one is Damian Nightshade. He's an OC who was experimented on by Dark wizards as a child, which gave him some strange and powerful Dark - related abilities. He then has to figure out how to live with these abilities and not be consumed by the Dark side.
A rather fascinating Dark OC is Raven Mordred. He's an outcast in the wizarding world due to his appearance and his natural inclination towards the Dark Arts. However, he's not truly evil. He just has a different way of looking at magic. He often gets into trouble with the Hogwarts authorities because he experiments with Dark spells in his own way. And then there's Luna Nightingale. She's an OC who was influenced by a Dark spirit when she was young. As she grows up, she has to fight the dark influence within her while also trying to fit into the Hogwarts community.
Chapter 584, "The Wealthy Young Master Renounces Worldly Life for Love", is the clearest early answer because it turns Bai Lu's situation into a concrete plot event. The chapter gives readers a real answer by opening on There wasn't a mirror on the small boat.
Chapter 703, "Slap Oneself", is the clearest early answer because it turns Zhao Lang's situation into a concrete plot event. The chapter gives readers a real answer by opening on Wu Daoshan quietly raised his head to size up Zhao Lang, and sure...
Chapter 509, "Don't Cry Funeral Until Someone Dies", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Because of the commotion from the night before, Jiang Li had...
Chapter 476, "Make a feint to the east but attack in the west, take something out of a bag effortlessly", is the clearest early answer because Make gets a payoff that changes the stakes.
Chapter 396, "The Shang Family Now Follows My Orders", is the clearest early answer because it turns Shang Shaojing's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Doomsday Beehive" featured a male supporting character who was...
Chapter 547, "What a bustling family you all are", is the clearest early answer because it turns Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on Because of the unsightly scandal caused by watching the live...
Chapter 457, ""Back Against the Wall", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. It opens with Five minutes later, he stared at Yu Li with his twitching mouth... and closes on How could he know what this mad fortune-teller was up to?.
Chapter 779, "Unmarried but Have a Daughter?!", is the clearest early answer because it turns Chen Qijun's situation into a concrete plot event. It opens with Right, there's one more important thing," Shen Lan looked at Chen...
Chapter 477, "Brother Pig, Don't Be Afraid", is the clearest early answer because it turns Yu Li's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Alright then, everyone come over and eat while it's still hot." Jiang...
Chapter 561, "How Can This Young Master Use His Hands to Kill Fish?", is the clearest early answer because the violence around Chen Manman becomes final instead of hypothetical. It opens with She had saved Luo Xuan that afternoon, and he already owed her one.