While not thrill rides, I always loved that little strip of Fantasyland at DW in the 70s and 80s that had Mr. Toad's Wild Ride and Snow White's Scary Adventures - the latter of which would seem to fit into the Villian's Land style - it was family friendly but a little darker and focused on the villain. I was only 3 years old when I first hit MK in 1971 when it opened, and for those early years until I was about 9-10, I loved both rides and did find them a little scary. The train tunnel and devil room on Mr. Toad's, and the witch in Snow White popping up throughout were scary enough to give me a little fear thrill but not enough to scar me or keep me off the rides.
I can't say I'm much of a Villain fan, but wouldn't mind the addition - though I'd be more into the theming than the rides. I'm not a roller coaster fan, so I'd be fine with some mild coasters, boat rides, etc - but with very deep, intense theming everywhere keeping with the mood. And as another poster mentioned, I would hope for it to be immensely popular, to keep more people in that section while I enjoy lighter crowds in the rest of MK.