Create a highly detailed, ultra-realistic 4K image of the demon Vecna from Stranger Things on a Black Luster Ritual, inspired by Charles Fremont Conner's style and incorporating elements of sci-fi and Lovecraftian horror. The artwork should feature highly detailed zen prisms, adhere to the golden ratio, and have a striking, vibrant color scheme with a predominantly dimmed atmosphere, high contrast, and soft lighting. The focus should be on Vecna's menacing, evil presence, with 'green man' elements subtly integrated. Ensure the image has micro and lifelike details, utilizes the Unreal Engine 5 or Octane Render for an 8K quality output, and meets the standards of trending artworks on Artstation and CGSociety. No additional legs should be added to Vecna's depiction.