So I was first introduced to the character Wonder Woman by the classic Super Friends cartoon, and the remake known as Justice League. One of my favorite villains in the JL cartoon was Hades especially because he was revealed to be Wonder Woman's father. I've always found Hades to be the most interesting of the Olympian trio especially because in the mythology contrary to modern portrayals Hades was arguably the most honorable of the gods because he never cheated on his wife and he actually took his job seriously.
That being said how would you feel if he was made into a more prominent figure in the Wonder Woman comics and made into Woner Woman's father? I know apparently her father is Zeus but I figure that could be retconned like it could come out that Hades disguised himself as Zeus(there are stories of Zeus disguising himself as a woman's husband to seduce her so this would be a good spin on that) and seduced Wonder Woman's mother to spite Zeus.
As for the kind of villain he could be maybe he might not go after Wonder Woman knows but rather people he views as a threat to her. Like for example since she's involved with Superman (or was I don't know if they are still together) say Superman started a emotional affair with Lois Lane and was leaning towards cheating and members of the League were aware of it so Hades tricks the League into entering the underworld with plans of torturing Superman on every level even using the souls of his birth parents to do it.
Ultimately forcing Wonder Woman to save Superman whose being tortured like this.
I like this idea because I think it would be interesting to see how she'd react to a villain that does terrible things to people as a weird messed up way of looking out for her?