I tihnk the reason why there aren't many fics set in a dystopian Crystal
Tokyo, while there are plenty where Crystal Tokyo would be dystopian, if
it came to exist, is fairly simple.
For the later type of fic, only one character need be made evil, Sailor
Pluto. Since she's somewhat of a cipher, that's easy enough to do
without seeming silly. On the other hand, to do a fic set in a
dystopian Crystal Tokyo requires an evil Sailor Moon, and probably most
of the other Senshi. That is, in my opinion, very hard to do without
becoming ludicrous, given the characters' canon personalities.
Anyway... RazorclawX's "The Geometry of Shattered Souls" is somewhat a
fic about a dystopian Crystal Tokyo. It can be found at:
http://www.angelfire.com/art/rcxshizuka/sm/smff00.txt