As far as I understand, the “adrenochrome” meme was initially inspired by Hunter S. Thompson’s mentions of it in Fear and Loathing, but some good reason to think he was a spook would explain things imo, which does exist.

My take on things was it’s the blood, especially when harvested from an emotionally charged (I.e. horrified) victim. The adrenochrome, given its legality and common mention in pop culture, is likely a red herring.