New Stranger Things theory: Brendon Urie is the Mind Flayer. In season 2 we never see the Mind Flayer in detail. So I would like to propose that in season 3 or maybe even season 4, we will learn the Mind Flayer's true identity. The plot for season 2 of Stranger Things has been right in front of our faces, concealed in the LA Devotee music video for months. I would like to suggest that perhaps there are more hints at what's to come in future seasons in other P!ATD music videos.