Alucard and Dracula

It might seem easy to have a hero come from a villainous family.  Yet, you might want to put some nuance in there to really make an impact.  What are some things to consider with this background?

1. If you want to make the reveal as soon as the hero appears then you should establish the evil family beforehand.  Having him show up and bluntly say that he’s the black sheep of a dark lineage can reduce the impact.  The whole thing will come off as casual and rushed, especially if it’s early in the story.
2. The hero doesn’t have to be an anti-hero.  It could be that they are the entire opposite of their family in an attempt to distance themselves completely.  For example, a hero who comes from a family of assassins may refuse to kill.  They won’t do it for any reason, which gives their family a way to try and corrupt them.  The point is that they don’t want to be associated with their evil lineage and might even be afraid of taking any action they would do.
3. Tying into #2 is giving the hero a fear of falling into the abyss.  Coming from a family of villains means a person will worry that such darkness is in their nature.  It doesn’t matter if they have been raised to be a hero.  They can fear that a part of them is tainted simply by the blood in their veins.  So, they can be extra cautious about their actions as well as easily manipulated by their family.  A plot point that can be done here is a situation where they have to take action similar to their family’s crimes or risk letting someone die.
4. Come up with a reason as to why the hero isn’t with the family both physically and morally.  It doesn’t really work to have them simply ‘not like it’, especially if they grew up in that darkness.  There are plenty of reasons why they turned even if it’s something selfish.  A non-family member they loved could have been killed for business, which had them realize their dark actions.  Another option is that there was a good-hearted family member who raised the hero instead of the others.
5. While I said the hero doesn’t have to be an anti-hero, that’s still an option.  It would work really well with a hero who spent time as a villain.  They might not be able to get all of their darker impulses under control such as using violence to reach their goals or even manipulating others.  This a character who might still be dark, but not evil.  It would also mean that they could have violent intentions towards their family.
6. A hero from a villainous family would most likely change their name to avoid the connection.  This isn’t only done out of shame.  They would be aware of their surname’s reputation, which would make it difficult to do good.  People who know of their lineage would automatically assume their are villains, which could lead to misunderstandings and being attacked.  It would be much more practical for them to keep it a secret unless they have a need for the reputation or can avoid its influence.
7. Don’t forget to give some attention to the villainous family’s opinion on the hero.  Do they think the person is weak or even an enemy?  Could they want them back?  They might want to corrupt the hero not to bring them back to their side, but to prove a sense of moral ‘superiority’.  They are the other side of the coin with this story, so you need to give them some attention.