I have a strange copy of Spain of a betamax..... 
It is not very good copy but better than anything...
Betamax was also my first video format, and I still sob for the lost war against the much poorer format, VHS, imposed by the massive north-american production.
Thank you very much for the rare video cover art. Someone pointed already that the photo on the back is from a different film, but the worse with your Spanish dubbed copy may be the distortions introduced to the original text...
The title was Le ombre roventi, literally The violent shadows, which is fairly given by the actual title, Shadow of Illusion... People have noted how the film has better fantasy scenes of dellusion (induced by drugs or otherwise), than violence proper. The Spanish title misreads «le ombre» as «hombre», man in Spanish! Therefore, just one more «violent man», instead of a fanatic occultist, eager to lead his people, followers of Osiris, to accomplish a blood ritual in the person of a (supposedly) reincarnated Isis! If the rest of the translation is as bad!...