X-Men #20

Published in May 1966, X-Men #20 arrived during a period of creative transition for Marvel Comics. Written by Roy Thomas and illustrated by Werner Roth, the issue serves as a pivotal installment in the Silver Age of comics, focusing on the team's ongoing struggle against the menacing Lucifer. The narrative reflects the recurring themes of the era, emphasizing the isolation and tactical development of the original five X-Men under Professor Charles Xavier's guidance.

The visual aesthetic of this issue is defined by Werner Roth, who often worked under the pseudonym Jay Gavin. Roth took over artistic duties from Jack Kirby, bringing a more grounded, illustrative style to the series that complemented Thomas’s narrative expansion of the mutant lore. While the issue is now viewed as a staple for completist collectors of the original series, it was produced during a time when the X-Men were still establishing their footing against more prominent Marvel titles, leading to the experimental plotting often found in these early mid-sixties issues.