ADVENTURE COMICS #375

Image is upside down but shows a Silver Age DC cover with 12¢ price, no barcode (pre-1977 so no direct/newsstand distinction applies). Visible wear includes edge and corner softness, slight surface sheen loss, and what appears to be a small crease near the lower right corner of the cover; spine area is obscured by the plastic sleeve and not fully assessable. Colors appear bright with no major color breaks visible, but resolution and rotation limit precise grading. Interior and back cover were not assessed.

Adventure Comics #375 arrived during the run in which the Legion of Super-Heroes had taken over the title's lead feature from Supergirl, and it holds a specific claim on Legion history: the first appearance of Mordru the Sorcerer, one of the team's most enduring villains. The story was scripted by teenage writing prodigy Jim Shooter, with art by Curt Swan and George Klein, and it introduced a mystically powered antagonist whose sorcery set him apart from the era's typical super-scientific threats, giving the 30th-century team a recurring foil that has persisted across multiple Legion revivals and adaptations into the modern DC Universe.

Market data for the issue reflects a book with steady but modest collector demand: sales cluster in the $50-$100 range through the midgrade tiers, with a pronounced jump only at the top of the certified population, where 9.6 copies have traded near $300 against a thin supply of four census copies and no examples yet graded 9.8. This pattern is typical of a recognized Bronze-adjacent Silver Age key that is genuinely scarce in top condition but not broadly chased outside Legion-focused and Mordru-specific collectors, keeping demand real but comparatively contained relative to flagship superhero first appearances of the same period.

The issue suits collectors building a Legion of Super-Heroes key run or a villain-origin theme, and it trades in a fairly linear, low-volume market through the low and midgrade tiers before spiking sharply at the high end, where census scarcity rather than broad demand drives price. Buyers assembling a complete run of Adventure Comics' Legion era, or those tracking first appearances of long-running DC villains, represent the natural audience, while a 9.8 or better copy would likely draw outsized interest simply due to its absence from the current population.