I'm kinda more a fan of having multiples encounters with a really strong opponent. Not for him to trash us all the time though. It'll be nice to have a rival, someone who's on par with you, and sometimes lose, sometimes wins.
I like it the best when they're slighly weaker, but wins anyway 'cause of a smart move or a well-devised tactic.

I'm not fond of schemers though! I kinda think we're missing a "loveable villain" in this game. Somewhat iconic and appealing, for whatever reason. Fighting faceless/masked entities is not as fun as having a identified ennemy who's going to give you hell.

Buuut... that's a plot-wise decision that I respect!
(I do think we're not focusing enough on each villain. They're dying a bit fast.)