>she intended him to be [...] a dark dreaded force rather than a direct villain
See, that's kinda what I'm saying. He WAS that. The dark, dreaded force of corruption. Or rather, what corruption can do to someone with power & influence (like, say, a Princess of Magic).
If that was the specific feature of Sauron that Meghan was trying to capture, I'd say she did an alright job. Sauron himself was an Ainur spirit whom Melkor had twisted, after all. If she was trying to make a hyper-competent master-manipulator with warlike aspirations, not so much.