Dive into the heart of the X-Men saga with issue #239, a pivotal chapter featuring the first appearance of Onslaught. Published in 1996, this comic book is a treasure for fans and collectors alike, showcasing the work of renowned artists and writers such as Mark Waid and Andy Kubert. It's a Copper Age classic that brings together iconic characters like Cyclops, Storm, and Firestar in a narrative that set the stage for future adventures. Marvel Comics' X-Men #239 comes in English language, a softcover format issue, and is graded as a 6.5 Fine+. This comic is a must-have for its role in the Marvel Universe and the legacy it carries. Whether you're a long-time enthusiast or new to the superhero genre, this piece of comic history is an essential addition to any collection.