Avengers & X-Men: Axis

Marvel's 2015 event series Avengers & X-Men: Axis is a nine-issue crossover (not a single issue) that pits Earth's Mightiest Heroes and the Children of the Atom against the inverted Red Skull, who has stolen the power of Charles Xavier. Written by Rick Remender with art by Adam Kubert, the story flips the morality of key characters, forcing heroes and villains to swap alignments in a high-stakes battle for the fate of the world. This series matters as a pivotal, inversion-fueled chapter in Marvel lore, reshaping the dynamics of both teams for years to come.