Clive Barker is one of those unfortunates like Stephen King and even middle-era John Carpenter, his ideas are bigger than the medium of film and are therefore tough to capture. Barker himself directed this movie and was a little hamstrung by special effects limitations.
Lord of Illusions is one of those potboiler action/horror stories that presupposes we live in a world of real magic. Stage magicians, long thought harmless, are tapping into real magic with some of their tricks. The movie begins with a doomsday cult almost winning, a few members turn on the leader (Nix) and imprison him beneath the Earth. The movie picks up years later as Nix's cult is on the verge of resurrecting him and a private detective named Harry D'Amour (Scott Bakula) gets sucked into the conflict. There are betrayals, secrets revealed at the Magic Castle, steamy sex scenes and lots of gruesome uses of magic to hurt others (or appear hurt yourself).
Still not my favorite of the occult detective genre (that would be Cast a Deadly Spell) but not bad. Like I said at the onset, Barker's imagination is bigger than his budget. He can't help that a lot of the green screen work looks dated now. This is a B movie if ever there was one.