Conversation so far:
How did Voldemort's character begin?
Rowling said Voldemort was invented as a nemesis for Harry Potter (the protagonist of the novels), and she intentionally did not flesh out Voldemort's backstory at first.
Why did rowling do that?
The basic idea [was that Harry] didn't know he was a wizard ...
And so then I kind of worked backwards from that position.

Question: How else is voldemorts character developed?
Self-contained rewrite: Besides fleshing out Voldemort's backstory of being a wizard, how else is Voldemort's character developed?