I could so do it. Maybe. Possibly. I remember I made a map of that dark cave near the start of the game. It only worked halfway, of course, since if you go into the second screen while it's 100% dark, you get knocked out and teleported to the entrance.
I own Wizard's Keep, a target I was looking at since the start of the game. I also picked up Castle Coldrake since it has Drake in it, and it looked like it had a second exit. Which it did, and I got 2 stat potions for it.
EDIT: Oh yeah, I have 3 out of 4 parts of the Skystaff, and I have a spare Skystaff Base, which I might be willing to sell if the price is right . .. . . . . ... . .