Jian’s body cam captures a startling moment of life and death. Submerged in sweat, Gong Soochan shows worrisome signs of an unusual infection.

Holiday mayhem, including “Black Christmas,” “Krampus,” “Silent Night Deadly Night,” “Terror Train,” “My Bloody Valentine,” “Mother’s Day,” “April Fool’s Day,” “Happy Death Day” and the 2018 “Halloween,” featuring returning guest…