Ah, but in the lead-in lies a flaw.
Some time after releasing the massive crossover in paperback form, Marvel made the wise decision of releasing "Age of Apocalypse Prelude." Within, we see the return of Charles' son David Haller aka Legion, his declaration of intention to change history by going back in time to kill Magneto, and Charles dying by his hand instead. As Xavier sacrifices his life to save his friend, Magneto pledges to carry on Charles' dream in his stead.
However, a major side-effect of Legion's actions is often overlooked when it comes to describing this as "the world where Xavier didn't form the X-Men." The creative team makes a choice to implant Apocalypse as the main villain of this world by having him detect the discharge of mutant energy and begin his plans to eliminate humanity a full decade earlier than originally intended. What this does is slightly undermine the concept. Yes, the "Age of Apocalypse" is a world without Xavier. But with that massive change, it is not necessarily the world.
Now that I have that little tiff out of the way, let me tell you: the prelude to "Age of Apocalypse" is almost as good as the actual story. Legion, for instance, makes for a far better villain. What he lacks in Apocalypse's stature, he makes up for in wild appearance. His hair, his poses and his facial expressions are frightening. David is - for what it's worth - an extremely dangerous escaped mental patient and every iota of that is played up in his presentation... though not flawlessly. There's a strange moment where an Oedipus complex is hinted at which comes up out of nowhere and then is dropped just as quickly. Seems like an editorial error more than anything.
The moment, though, where David confronts his father in a dream sequence is genuinely chilling and sells the storyline. For many X-Men fans who came aboard in the 90's thanks to the cartoon, this was their first look ever at Legion. "Wait, who IS this guy? Check out his hair. Charles Xavier has a son?!" His appearance along with his deep understanding of Xavier and his father's friendship with Magneto puts him over as an immense threat. And then he fulfills that promise.
As mentioned, David goes back in time and - long before the killing stroke - the reader discovers that he has been successful in altering the past. The fact that it was not to his liking is kept under cloak. Standing in the present and knowing that they have failed, the X-Men who did not follow Legion back in time are forced to sit and wait as the universe is obliterated. With little time left, Cyclops and Jean Grey confess to Cable that they were "Slym" and "Redd," the two people who raised him in the future. His response is... surprising, given earlier interactions. Wolverine and Sabretooth have a battle with a shocking conclusion (which is disappointingly not included in this set,) and Rogue and Gambit finally make human contact.
Then, in a cool effect, all of planet Earth is coated in a wave from the M'Kraan Crystal. The X-Universe, as it was known, is gone. It's an incredible moment with well-written gravitas.
In short, this collection is excellent but there is one big problem: the print quality. For whatever reason, Marvel chose this book to experiment on the paper type for its paperbacks. Up until this point, they had been covered in a glossy sheen not unlike hardcovers or the single issues we've been able to buy for the last 20 years. Instead, what we get is something that's only slightly better than newsprint. Marvel eventually did opt to scale back its production on its older TPBs, but it was still a step up from this. The incredibly light weight of this collection is almost unsettling. It's enough that I keep this sealed in a bag for fear of deterioration. On the bright side, "Legion Quest" is collected in volumes now with superior paper. Unfortunately, the issue of "Uncanny" where he first threatens his father and the issue of "Cable" which expands on the last few moments of the heroes left behind are not. It's a shame, and it forces me to knock off a few marks from the final score.
Rating: 6.5/10* (-2 for paper quality.)