Conversation so far:
In what way was Lord Voldemort's character developed?
At first, J.K. Rowling didn't flesh out Lord Voldemort's backstory. But as the series continued, she started adding more and more to his story and character.
What was Lord Voldemort's character like?
Rowling described Voldemort as a self-hating bully, a psychopath
Did Lord Voldemort use magic?
Yes, as he was a wizard, he used magic

Question: did he ever cause any harm to Harry Potter?
Self-contained rewrite: Did Lord Voldemort ever cause any harm to Harry Potter?