I'm a little surprised that the title of this series isn't "Dark X-Men: The Return of Nate Grey" since that would be a little more accurate, and possibly pick up a few readers along the way. While focused through the eyes of Norman Osborn's pet team of mutants, the center of this series is Grey, the mutant shaman known as X-Man, and his return to this plane of existence. Paul Cornell and Leonard Kirk give that return the importance it demands considering Grey's power, but it does shunt the eponymous Dark X-Men off to the side a little.
With Grey returning by taking over the minds of a town before retreating, Osborn is naturally concerned and has two options: recruit Grey or kill him. He opts for the latter because of Grey's power, which is so considerable that it's not worth the risk. He's already got one dangerous powerhouse in the Sentry that he doesn't need another, one more inclined to fight for what's right at that. Dispatching his X-Men to do the job leads them to a pet project of Osborn's involving a group of hive-minded telepaths that is nearly off the creepy charts and don't quite do the job they're asked of.
Cornell's handle on the Dark X-Men is quite strong with each pulling in a different direction even when they have the same goal. Mystique just wants out, while the Beast wants living toys to experiment on, and the Mimic seems to have lost all sense of caring what happens after he sees his own future. In many ways, this team is more complex and diverse than the Dark Avengers, which is a group that has conflict for the sake of conflict, not so much because each member has its own unique agenda. Here, none of the teammates are on the same page, which is refreshing.
The biggest problem in this comic, though, is the pacing. The slow, plodding pace means this issue ends on a plot point where, ideally, the first issue should have ended on (since the spoiler of Nate Grey returning was out of the bag). Two issues of build-up and Grey barely appears. Normally, that sort of build-up makes a character look impressive, but, here, it doesn't; it makes the comic read worse.
Leonard Kirk worked very well with Cornell on "Captain Britain and MI:13," and brings that collaborative skill to this project. The two clearly trust one another and work very well together as Kirk draws some outrageous things in this issue, including a big ball of telepaths. And he does so with great skill.
"Dark X-Men" is a good comic, but the slow pace makes it drag a little. However, Cornell and Kirk's strong character work nearly makes the slower pace worth it as we get to spend more time with this diverse cast and get inside their heads a bit