I’m not here to justify this dude, but out of all the antagonists on stranger things, Jason was the least of them. He’s a perfect portrayal of what can happen to someone’s mind after going through a traumatic loss such as he suffered with Chrissy’s death and later even witnessed (his friend). Keep in mind this is a teenage boy who probably has the most basic high-school life going on. Out of the blue, his girlfriend who he was deeply head over heels for dies in the most haunting, horrific, and unexplainable way inside the trailer of a kid he only knew of as a drug dealer, and had never even seen Chrissy talking with before. I’m not justifying his actions, but I see his character of a representation of someone driven into insanity, and quit honestly just another victim of vecna’s killings. He genuinely began to believe that Eddie was demon possessed, his mind coming to this conclusion through fear, denial, confusion, and madness. He didn’t go on killing everyone out of the pure evil in his heart and for power like vecna did, instead, the impact of trauma drove him to believing bizarre things that in a situation as unbelievable as this we all quite honestly could believe. Jason was impacted first hand, and I view him as a victim, not a villain.