The Avengers #166

The cover — penciled by George Pérez and inked by Ernie Chan — makes a striking promise: Count Nefaria stands at the center, blasting energy that sends both the Vision and Thor reeling, his boast that even the Thunder God is helpless before him blazoned across the image in bold challenge. Thor looms massive in the foreground, Mjolnir raised yet clearly on the back foot, while the Vision charges in behind — and still Nefaria looks supremely unconcerned. Billed as "the saga you never expected to see — Nefaria Supreme!", this December 1977 issue of Earth's Mightiest Heroes sets up one of the Avengers' most formidable villain confrontations with real visual flair.