X-Men

Avengers vs. X-Men Omnibus — the Phoenix Force returns to Earth and splits the Marvel universe. Captain America vs. Cyclops, the Phoenix Five transform the world, Hope Summers as the chosen one. The event that changed everything. Avengers vs. X-Men #0-12 plus AVX: VS #1-6 and AvX Consequences #1-5 collected in the complete omnibus. The Phoenix Force returns to Earth targeting Hope Summers — Captain America demands she be handed over, Cyclops refuses. Twelve issues of Marvel's biggest superhero war: the Avengers fighting the Phoenix Five (Cyclops, Emma, Namor, Colossus, Magik with Phoenix power). Ends with Cyclops in prison and the mutant population beginning to rise again. The event that launched the All-New Marvel NOW era.

X-Men: Mutant Massacre Prelude Omnibus is valuable because it treats the crossover as an approaching disaster rather than a sudden event. Claremont-era threads around the Morlocks, Rachel Summers, X-Factor, New Mutants and the Marauders build a sense of dread before the attack arrives. For X-Men collectors, this is setup as much as story: the world before the massacre, with every fault line already visible.

Chris Claremont assembles a dream team of artists — John Romita Jr., Arthur Adams, Barry Windsor-Smith and Dave Cockrum — for this massive fifth omnibus collecting issues #194-209 plus the complete Longshot and Nightcrawler limited series. The Juggernaut makes an earthshaking return, the second Lifedeath story explores Storm's journey without powers, and the Asgardian Wars crossover sends the X-Men and New Mutants into Norse mythology. Nathan Summers is born and Rachel Summers grapples with the Phoenix Force, while Barry Windsor-Smith crafts the defining Wolverine solo tale Wounded Wolf. This volume also introduces Longshot, the lucky six-fingered warrior from the Mojoverse, in Arthur Adams' career-making limited series that became an instant classic.

Uncanny X-Men Omnibus Vol. 4 is the mid-1980s pivot where Claremont's mutant soap opera becomes harsher, stranger and more visually muscular. Storm loses her powers but becomes more formidable as a leader, Rachel Summers brings the Days of Future Past trauma into the present, Nimrod appears as a terrifying future Sentinel, and Kitty Pryde gets one of her defining solo journeys. John Romita Jr. gives this era a bold, angular energy that makes the team feel less polished and more dangerous.