He could be extremely protective. Since he was a normal person before turning into a vampire, he would have a strong sense of protecting those he cares about from the dangerous vampire world. This could be his friends, family or even new acquaintances he meets on his vampire journey.
He might also be very alluring. Vampires are known for their charm, and Henry Lau would likely have an added allure as a vampire. This could attract people to him, both in a positive way like making new friends or in a negative way where other vampires might be jealous of his charm and try to undermine him.
Romance is a very common theme. Often, Henry as a vampire falls in love with a human, creating a lot of tension and drama due to the differences between their natures.
One great 'Henry Lau vampire fanfiction' is 'Eternal Night with Henry'. It weaves an exciting story of Henry as a vampire in a modern city. The author does a great job in creating a dark and alluring atmosphere.
One possible plotline could be that Henry Lau, after turning into a vampire, struggles to come to terms with his new identity. He might try to hide it from his friends and family at first. For example, he could be a famous musician in his human life, and now he has to find ways to continue his career without revealing his vampiric nature. He may have cravings for blood that he tries to resist, leading to internal conflicts.
Well, Si could have a strong sense of loyalty. As Ruby's twin, he would be deeply connected to her and by extension, her friends. He might be a bit of a strategist, always thinking a few steps ahead. He could also be more in touch with his emotions than Ruby, who sometimes seems to be all about action. This could make him the one who provides emotional support to the group when things get tough. And perhaps he has a creative side, coming up with unique solutions to problems that the others might not think of.
Henry's daughter might be intelligent. She could be well - read and have a great knowledge of history, magic, or politics. This intelligence would help her solve problems in the fanfiction, like outwitting an enemy or coming up with a plan to improve the kingdom.
The son could be highly adaptable. Growing up with two such different fathers, he would be exposed to different ways of thinking. He might have Draco's slyness when it comes to getting out of tricky situations, but also Harry's selfless nature when it comes to helping others. He could also be very good at magic as he would inherit the strong magical genes from both his fathers. And he would probably be a bit of an outcast at Hogwarts, not fully fitting into either the Slytherin or Gryffindor mold.
The child might be very empathetic. Yuki is known for her kind heart and Kaname has a certain depth of emotion. Their child could inherit this and be able to understand the feelings of others, whether they are vampires or humans. This would make the child a great mediator in the often - tense relations between the two species.
In fanfiction, he could be a very curious vampire. Jungkook is known for his eagerness to learn new things in real life, and as a vampire, he might be interested in modern human culture. He could be nocturnal, of course, and have a heightened sense of hearing and sight. His loyalty to his vampire clan or to his human friends would be a strong character trait, and he might be conflicted when the two worlds collide.
He could be extremely resourceful. Since he's alone in a world full of challenges, he has to be able to find food, water, and shelter on his own. For instance, he might know how to build a shelter from scraps and hunt small animals for food.
She could be very clumsy. Without her glasses and under the influence of alcohol, she might trip over things easily or bump into people. Also, she could be a bit more vulnerable. Losing her visual aid and being drunk makes her less in control, so she might be more open to help or kindness from others.