The Defenders #16

From October 1974, this issue of Marvel's non-team book pits the Defenders against a truly overwhelming threat — the cover announces both Magneto, the Brotherhood of Evil Mutants, and the ominously titled "Alpha the Ultimate Mutant Menace" all in one issue. Gil Kane and John Romita's cover (inked by Giacoia, Romita, and Esposito) delivers a stunning visual: a massive, bald, glowing-eyed figure looms over everything while the Hulk, Doctor Strange, the Valkyrie, Nighthawk, and their chained companions struggle below, with Brotherhood members joining the fray. It's a genuinely crowded, kinetic composition that makes it easy to see why Len Wein and Sal Buscema's run on this series found such an enthusiastic audience in 1974.