This movie is nothing more than an attempt to cash in on the first one's success. Julian Sands once again returns as Satan's son, but he seems to be sleepwalking this go-round. Two disposable teenage actors (Paula Marshall and Christopher Young), play two descendants of Druid warriors who are the ONLY people who can fight the Warlock and prevent him from releasing Satan into Earth. Oh, and there are six rune stones or something he has to possess to unlock Satan from the bowels of the Earth (etc.etc.). You get the idea.
Anyway, this has some pretty decent effects, and some pioneering computer animations, but all in all, it's a very weak film, and, putting the special effects aside, there's not much left but incompetent acting and cheap thrills. If you like the Warlock films or love Julian Sands, buy this one, or if you're curious, buy it, but overall, you could skip it without really missing anything.