The plot of this movie doesn't make a great deal of sense. Part of the problem is that the subtitles on the print I saw were very small, (the VCD that I have is a widescreen print with the subtitles from the actual film itself so they end up being very tiny). Another part of the problem is that this movie wouldn't make sense under the best of circumstances.
It all begins when two women buy a vase at an auction. The younger of the women takes it home and becomes "possessed" by it. What this means is that a big ugly monster comes out and has sex with her and changes her personality so she is obsessed with the vase. One night hubby comes home and sees his wife with the monster and is killed by the beast. The wife, now pregnant soon gives birth to a mini monster and dies. The mini monster is caught and then things get less clear. (That's about the first 12 minutes of screen time.) From here the "monster" jumps from body to body killing people and eating dead bodies, he keeps under a bed.
I can't really tell you much more about the plot than that, except that the movie has several great set pieces mainly battles with the monster in human form, one with a priest who uses mini statues and the final one in the cellar of a house (That one had me murmuring "oh s#&%" a couple of times). There are numerous gore effects and moments of gross out horror. Best of all at times the movie achieves a wonderful nirvana when you're sitting there with a combination of being grossed out, a desire to laugh at the cheesiness of the visuals and a deep admiration at a film that is over coming everything to have a "really cool" moment.
Understand, though, this is a mess of a film. It doesn't really come together well. There is the slenderest of threads keeping it all together (and it could be argued its not very together). The strength of the movie is its parts, the set pieces and gross out horror bits, this is the reason to see the movie and not for any hope of a clear plot.
As a whole this film is really probably a 7 or 6.5 so when I was rating it at IMDB my giving it an 8 was over selling it on the basis of its parts, but I was really impressed by the parts. If you like gory horror and don't mind a lack of sense try it.