Spoiler alert: Don’t learn when you have not watched “Chapter 9: The Piggyback” of Stranger Issues 4, now streaming on Netflix. Whereas we course of the pandemonium of the heart-pounding Stranger Issues 4 finale, let’s revisit that chilling “Snow Ball” scene and its badass classic turntables. When this season’s villain—a darkish wizard named Vecna who feeds on the trauma of youngsters—closes …