WARNING: The following contains spoilers for Cable #12 from Marvel Comics, on sale now
Thanks to his time-hopping adventures, the former X-Men and X-Force leader Cable has found himself locked in an ageless and endless war against his dark reflection, Stryfe. Their conflict has spilled into the modern-day multiple times, with one side gaining a definitive victory in their overarching conflict.
In Cable #12 by Gerry Duggan, Phil Noto & VC's Joe Sabino, the two versions of Cable are able to team up and kill their nefarious copy, Stryfe. But the battle might not be over once and for all, especially if the telepathic threat can find a new body to utilize.
Introduced in New Mutants #87 by Louise Simonson and Rob Liefeld, Stryfe is the clone of Nathan Summers. Taken into the distant future in an attempt to save an infant Nathan from the Techno-Organic Virus, the Askani Cult created a copy of him in the event of his death. However, the clone was captured by Apocalypse and instead raised as a dangerous and devious threat. Quickly becoming a time-hopping villain to his "brother" Cable, Stryfe returned to the present-day and brought chaos to the world by infamously creating the Legacy Virus, leading to untold suffering and death in the mutant community. Even with the original Cable dead by his younger self's hand, Stryfe has remained a threat to him and the mutant nation of Krakoa.
The young Cable has done everything in his power to counteract his plans, which have been slowly revealed to involve sacrificing a number of mutant infants as part of a demonic deal to invade Earth. With no other option, the young Cable is forced to revive his older self, eventually ensuring he'll have to return to his proper place in the timestream so he can grow to become that version of himself. However, this gives the X-Men and their allies additional help against Stryfe and his forces. Hunting him down to a hellish dimension where he's taken up residence, the two Cables lead a team of friends and family against Stryfe. Working together, the heroes are able to save the babies, send the demonic army running in the other direction, and even contain Stryfe's notable powers.
Together, the two versions of Cable confront their demented clone, guns raised. Stryfe tries to beg for amnesty, reminding them that Krakoa is meant to be for all mutants. But both versions of Cable -- claiming their ears are ringing -- simply turn to him and open fire. The two blasts leave a hole in his chest, killing him. However, as the older Cable explains, Stryfe has other cloned bodies in other time-periods. To contend with him, they have to fight him a "two-front war" -- requiting the young Cable to say goodbye to the friends and family he'd found on Krakoa so he can return to his proper place in the time-stream. It's a bittersweet moment for the young Cable, who had found acceptance and happiness on Krakoa.
But to keep Stryfe from becoming the true threat he could be without Cable keeping him in check across space and time, the younger Nathan returns to the future. Still, it's a victory for Krakoa, and should hopefully keep Stryfe out of the present-day for some time -- hopefully. There is one additional complication to their victory: when the mutant babies are returned to their parents, they come with cloned copies of them. While the parents are happy to have twins to watch over, as they leave one of the children is revealed to have Cable -- and Stryfe's -- trademark glowing eye. This hints that Stryfe may still have some connection to the present day, with the series ending on the tease of that story playing out down the line.