How bad is it? It's the worst-made, but not worst Deathstalker film.
Should you see it? No. It's just the first film repeated.
Roger Corman produced the series of Deathstalker sword and sorcery flicks. The first two were okay and the third got the MST3K treatment. This one brings back the star of the first film, which was probably necessary, as half of the film is footage repeated from the first film. There's a tournament of warriors, a magic sword, and the baddie is female this time. There's the standard types, the standard gratuitous toplessness, the standard poor swordplay. The editing is especially poor: in a chase scene, for example, you can see characters killed off earlier.