X-Men #18

Published in March 1966, X-Men #18 stands as a significant milestone in the early Silver Age of Marvel Comics. This issue features the first full appearance of the Factor Three organization and the mutant villain Banshee, created by writer Roy Thomas and artist Werner Roth. The story emerged during a period where Stan Lee and Jack Kirby were expanding the X-Men’s rogues' gallery to provide a greater threat to the team, moving away from the singular focus on Magneto and the Brotherhood of Evil Mutants.

The artwork by Werner Roth, who often worked under the pseudonym Jay Gavin, reflected a departure from Kirby’s highly dynamic, cosmic aesthetic toward a more refined, grounded approach that defined the middle years of the original series. While the issue was part of the ongoing struggle to establish the X-Men's popularity compared to the runaway success of titles like The Fantastic Four or The Amazing Spider-Man, it remains a sought-after piece for historians and collectors for its contribution to the expanded lore of the mutant universe and the debut of lasting characters.