The heroes of the Marvel Universe have dealt with countless existential threats over the years, and the X-Men have dealt with more apocalyptic futures than most. With no shortage of dark possible futures like "Days of Future Past" or the timelines that inspired the creation of Krakoa in House of X, there doesn't seem to be a question of if the X-Men's story will come to an end, only a question of how.
And starting in 2004, Marvel put forth one comprehensive look at how the X-Men's world might end in the X-Men: The End trilogy of stories by Chris Claremont, Sean Chen, and Sandu Florea. Now, we're taking a closer look at how this gave the X-Men one last saga that wiped out many of Marvel's most famous mutants.
X-Men: The End is split across multiple locations and settings. By the time this starts roughly a decade into the future, the X-Men have grown greater and larger than ever, even though many members have left the team and gone their own ways to start families. Some, like Havok, have even died. However, the X-Men are all united again when Aliyah, the daughter of Bishop and Deathbird, comes across a mysterious orb in space.
Alongside her mentor -- a computerized Carol Danvers -- Aliyah has been traveling the cosmos ever since Deathbird was used to rebirth the Brood, and Lifeguard sacrificed herself to protect her. Aliyah finds herself fighting against Hounds -- including Nocturne, Siryn, Multiple Man, and Slipstream -- for the orb. Discovering Jean Grey inside, Aliyah escapes with Nocturne and Slipstream teleports away, leaving Multiple Man and Siryn behind to die when the Brood attack.
Many figures across the universe feel Jean's resurrection, and many more secondary X-Men meet their ends in the early stages of the event. X-Force tries to rendevous with Cable, but the group is attacked. Meltdown, Shatterstar, and Warpath are killed and converted into tools for the Marauders. The Marauders even separate what remains of Apocalypse from Cable's partner Irene and destroy him using a bio-mechanical mutant called Techarax. Cable is infected with Techarax's version of the Techno-Organic Virus and captured.
Domino, Rictor, and Feral try to warn the X-Men but are attacked and killed by a mysterious shapeshifter. This is revealed to be a War Skrull, one of many shapeshifting assassins sent to Earth by the Shi'ar Imperial Councilor Khan in a bid to wipe out the X-Men once and for all.
More War Skrulls attack the mutants in the forms of characters like Yukio and Val Cooper, longtime allies who are also revealed to have been killed. Another group of War Skrulls attacks the Xavier Insititute alongside a restored Madelyne Pryor, who kills Dust and uses her clothing to hide amongst the X-Men. The attack on the Institute is devastating, killing many students as well as staff members like Wither, Juggernaut, Wolfsbane, and Northstar. A secondary separate attack on the survivors ends in the death of Banshee and grievously wounds Colossus.
The plans of Mister Sinister -- which included stealing the children of both Cyclops and Emma along with Rogue and Gambit -- start to fall apart when Dani Moonstar breaks free of his base at the old Weapon X facility Neverland. Dani dies and is restored as a Valkyrie. Sinister is able to lure Rogue into a trap and kill her, but her adoptive mother Mystique quickly repays Sinister in kind. Gambit takes Sinister's place beside Khan, hoping to find out more about the mysterious attacks from the Shi'ar, ultimately sacrificing himself to kill Khan.
Deciding to finally confront Lilandra, Xavier crosses the galaxy thanks to Magneto and Polaris creating an interdimensional portal with their powers. However, Xavier is shocked to find that in this reality, Cassandra Nova was never forced out of Lilandra, as she was in the Marvel Universe in the early '00s.
Her plans quickly turn on the X-Men. Polaris is killed, and Magneto reduced to a pure energy form by the Imperial Guard member Plutonia. Two teams of X-Men rush into Shi'ar space, including one team moving through the closing portal and led by Cyclops, with another space-based squad approaching the planet from the skies. While the X-Men battle the Imperial Guard, Cassandra Nova, and Xavier have a psychic duel that Xavier loses. As casualties like Archangel mount up on the battlefield, Nova is seemingly brought down by Cable unleashing his full powers, which leaves his body open to complete corruption by the TO Virus. Before Jean can save him, she and Cyclops are fatally attacked by Rachel Summers, who is revealed to have been corrupted by Cassandra in her attempts to rescue Xavier.
Cassandra takes the power of the Dark Phoenix herself and battles the X-Men. Many more heroes seem to fall in the battle, including the Imperial Guard, Dazzler, Captain Britain, and Sage. However, Madelyne Pryor reveals herself and fuses with Jean to fully restore her powers. This reconnects Jean to the Phoenix Force and allows her, Xavier, Cassandra Nova, the dead X-Men, and many of the other remaining heroes to bond with the universe and become one with the Phoenix Force itself.
By the time the carnage of this series is over, only a handful of X-Men are still alive. As a flash-forward to 20 years in the future reveals, the only surviving X-Men are Wolverine, Kitty Pryde, Psylocke, Mystique, White Queen, Nightcrawler, Iceman, Cannonball, Lila Cheney, X-23, Karma, Jubilee, Beast, Monet, Cecilia Reyes, Omega Sentinel, Nocturne, Bishop and Aliyah. In the story's finale moments, they gather together with their families to commemorate the anniversary of their friends' demise in a ceremony overseen by Pryde, who's now become the President of the United States.
While that might seem like a fairly large number of survivors, this series saw the slaughter of nearly as many mutants and veteran X-Men allies, with more having perished off-panel. Even though this saga ends with enough X-veterans to field a few teams, this story still stands as one of the deadliest X-Men timelines Marvel has ever explored.