WARNING: The following contains major spoilers for Marvels X #6 by Alex Ross, Jim Krueger, Well-Bee, and VC's Cory Petit, on sale now.
In the latest issue of Marvels X, the Baxter Building is under siege by violent and bloodthirsty mutates. After everyone on Earth was unceremoniously gifted with superpowers by way of the Terrigen Mists, many of them couldn't handle the physical and psychological changes, and they want Reed Richards' head for it. There is still one lone human left, the young David Jarrett, and the remaining heroes are doing all they can to keep him alive in the hopes of finding a cure.
While much of this series has shown how the world of Earth X will come to be, it ended with the suprising reveal that David Jarrett would become the mysterious immortal hero known as Daredevil in this alternate timeline.
The White Coats have lost any chance they had to study David and uncover the cure they sought when the mutates make it into the building. From that point forward the only option is to fight and protect David at any cost. The heroes put up a good fight, and don't pull any punches, but it just isn't enough.
When Captain America loses his shield in the fray, David picks it up. He's determined to get the shield back to Cap, and he decides to carry it. In one of the most emotionally charged moments of the series, David hands the shield off to Cap only to be stabbed through the back by a mutated Scorpion. The battle isn't even close to over, and though the heroes do begin retaking their ground, David is already gone.
Nighthawk arrives at David's grave later on, led by a vision, and he begins digging. David is seriously confused, and asks Nighthawk if he didn't really die. David is informed that he did die, and then he came back. David wasn't the last human on Earth, because there weren't any left. David's power is regeneration and resurrection, but no one could have known that because David had never died before.
Some number of years later, a new Daredevil is putting on his suit, and finally the identity of this Daredevil is revealed. It's David. Of course, after the big reveal that David does have superpowers, this all makes perfect sense. In Earth X, this Daredevil has always been an unknown in terms of who is behind the mask. Speculation has been lobbed at Foggy Nelson, Wade Wilson and even him being a Skrull.
First appearing in 1992's Earth X #2 by Alex Ross and Jim Krueger this Daredevil is something much closer to what his name would imply. Performing on television and in a traveling show, this version of the character performs fantastic stunts, often to his own demise, and occasionally just lets someone from the audience shoot him in the head. The fact that he gets right back on his feet after these gruesome killings is more than enough to make this Daredevil a household name.
But this wasn't all just for money and fame. Something much darker was hiding just beneath the surface of these performances. Daredevil wants to die. Daredevil so badly wants to die that he joins Captain America just for Cap's long history of dead sidekicks. But this attitude doesn't last. After a long series of events, including his decimated body regenerating into multiples of himself, Death finally comes for Daredevil and he hides. When questioned why he would do so after trying for so long to end his own life, he lashes out and admits that he is a coward.
It is unknown what happened to David after this. However, the mystery of who is behind the mask has finally been solved. Understanding who it is and how they came to be isn't just an end to the mystery, though. It's also a potent lens through which to reread the original stories with a new, more refined focus.