The following contains major spoilers for Strange #6, available now from Marvel Comics.
When Clea Strange took up her late husband's mantle as the Sorcerer Supreme of Earth, she knew that she would be stepping into a world of both fantastical and mundane horrors. What Clea never expected, however, was that the latter of those two would be the one to threaten both her world and that of the dead. Not only have the Blasphemy Cartel become one of Marvel's premier supernatural threats after seemingly emerging overnight, but they were also able to do so thanks to being born from the now former spy organization -- S.H.I.E.L.D.
Ever since the Blasphemy Cartel first emerged, they have become increasingly dangerous. Apart from launching multiple attacks on the new Sorcerer Supreme, the Cartel has somehow acquired the means to control the recently undead Marvel heroes and villains who have become a problem in their own way. As seen in the pages of Strange #6 (by Jed MacKay, Lee Garbett, Java Tartaglia, and VC's Cory Petit), it isn't all that surprising that the Cartel has such an impossible arsenal. At least, not after the revelation that they once belonged to S.H.I.E.L.D. was made.
During Wong's investigation, he comes to realize that his favorite bartender from the Bar With No Name is the former director of S.H.I.E.L.D.'s old Wizardry Alchemy Necromancy Department (W.A.N.D.), Pandora Peters. Both she and W.A.N.D. have been a part of the Marvel Universe for quite some time, having been introduced together in 2013's Thunderbolts Annual (by Ben Acker, Ben Blacker, and Matteo Lolli). In her time overseeing W.A.N.D.'s various operations, Pandora was on the front lines of the war against the dark side of the Mystic Arts, and that war has continued in the shadows in spite of the fact that S.H.I.E.L.D. is no more.
As Pandora explains, the personnel, resources, and artifacts that once belonged to W.A.N.D., like those of every other fallen organization, ended up somewhere else. In this case, that place just so happens to be in the arms of the Blasphemy Cartel. When S.H.I.E.L.D. was dismantled in the wake of the events of 2017's Secret Empire, much of what was once W.A.N.D. took a turn for the worse. Former agents became mercenaries, and eventually, the Cartel that poses such a threat today.
The Blasphemy Cartel may have been bad already, but this discovery makes them so much worse than anyone had any reason to believe. Though it explains where the Cartel got their training and arsenal, it also confirms that they aren't just random street thugs who came across a bevy of occult armaments. Instead of a random gang wielding weapons they can't comprehend, the Blasphemy Cartel are now highly trained, largely decorated agents who know exactly what they are doing at every step.
Assuming Clea can't single-handedly bring an end to the Blasphemy Cartel's machinations, it won't be long before they do a lot of damage. That might not be the best course of action for the Cartel, as doing anything to bring the full force of her Faltine fury upon themselves is nothing more than a recipe for disaster. Then again, now that the truth about the Blasphemy Cartel is out in the open, setting off the latest Sorcerer Supreme might have very well been their plan all along.