You can buy a demon mask online or at the many costume stores that in malls close to Halloween. Then all you need is a cape to complete the look and there you go. Masks and capes are also sold at Target & WalMart. If you prefer makeup, look at the ma...
Are you talking about literal masks or figurative masks? If the former, I really don't ever see people wearing masks except on halloween. If the latter, it is usually a defense mechanism.
It's called "Halloween 3: Season of the Witch" and has nothing to do with Michael Myers, though it is "technically" in the series. It is an awful movie, and I would recommend watching something else.