I am not a lawyer. Copyright violation is often up to human interpretation (not yours) by a judge or jury.
They get to decide whether you are stealing a character or not. Chances are, they will decide a lightning bolt scar, round glasses, etc is so unique it can't be anything BUT plagiarism, so they will find you guilty of copyright violation, perhaps trademark infringement, and theft of intellectual property.
Harry Potter's persona belongs to JK Rowling and her contractual partners. The underlying issue is, broadly, that you cannot steal somebody else's imagination in order to make yourself money. There are huge exceptions when it comes to generalities that you can show are present in multiple works over time. Nobody can stop you from writing a murder mystery, or clever super-observant detectives, or space operas like Star Trek and Star Wars, or about a magic school for kids, or magic portals to a magical land. You can write treasure-hunt adventures, similar to Indiana Jones but with different protagonists. Those things have been done many times, in print and film, and thus no particular person or entity owns them. You can follow plot points: Hundreds of romantic comedies follow the same broad plot, millions of novels adhere closely to the Hero's Journey.
But when it comes to specifics that exist in only ONE work, then you are in trouble. It doesn't make a difference what might happen "In Real Life", what matters is, how many authors can you find with a male character of that age with a lightning bolt scar and round glasses, etc. When you add enough characteristics of any kind to narrow the field to one, then you are in trouble. I imagine just the lightning bolt scar on the forehead is sufficient in this case.
I will also note that if found guilty, the penalty can be greater than just all the money you made. The offended party can claim your work has damaged their prospects by polluting and diluting their brand, and receive not only the money you made, but significant compensation for the damages as well.
But again, I am not a lawyer, you should consult one before you publish anything like this. Or follow my advice: Use your own imagination, don't try to take shortcuts using anybody else's; it is stealing.