Action #962, Lex Luthor, speaking of the mysterious craft that brought Doomsday to Metropolis: "This tech is foreign to me. I've worked with nearly every alloy known to man, and I've never seen anything like this before."
Action #962, Superman, speaking of the mysterious men who arrive to take Doomsday away: "With capabilities I haven't seen before. People I haven't seen before."
Superwoman #1, Lois and Lana, speaking of a mysterious laboratory where they encountered a something akin to a female Bizarro: "It's a lab of some kind." "But I've never seen technology like this before."
Flash #4, Meena, speaking of the mysterious lab where they encounter Joseph Carter / Godspeed: "This isn't S.T.A.R. Labs equipment. This is like… no technology I've ever seen."
Not only is the same idea articulated in all of these cases, even the words generally match.
Additionally, each of these situations introduces different antagonists who wear generally circular symbols on their chests and have their eyes obscured. They also involve enemies (Doomsday, a Bizarro, and the speed-stealing Godspeed) who duplicate the various heroes' powers. This is time for an obligatory, "Coincidence? I think not."
We already know that Action and Superwoman are linked – a cameo tied them together. If all of these similarities are not coincidental but design, then Flash is drawn into the intrigue as well. And if Flash is being attacked by the master plan as Superman, we are seeing the beginning of something that has to turn into a major crossover with Mr. Oz as one of the central players. As Superman says as he watches Doomsday being taken away, "Whatever this is, there's something bigger at play."
And what is that something? Early in the Superman-Doomsday battle, Mr. Oz, looking on from afar, says, "Rarely do the pieces fall into place so quickly. Much will be learned. Much will be gained." Later, he says to his telescreens, "Think, Kal-El – What will you do next? Only then can I make my move." What does 'Kal-El' do? He tries many battle tactics, and pursues Doomsday outside of the city, helping to protect his wife and family. None of this stands out as terribly surprising, but it seems to serve Mr. Oz's purpose, who later orders his team to "isolate" Doomsday. Why?
One of the stories in the Action arc is titled, "The Doomsday Protocol." That's a phrase that was used way back in 2005's Action #825. The term referred to a plan to vanquish a Doomsday-level threat by sending such a foe to the Phantom Zone. That appears to be what Mr. Oz is about to do. Why? Did he desire that this battle take place for a while but then end with the villain beaten? Is the plot of Flash showing another facet of the same master design?
It has been much speculated that Mr. Oz is really Ozymandias from Watchmen. There are also subtle hints that he could be Kryptonian: He has access to remarkable technology, he sent New 52 Superman a notebook bearing the 'S' symbols, which is Kryptonian in origin, refers to the current Superman as "Kal-El" and is, perhaps, about to access the Phantom Zone. Regardless of his origins, what is his plan? He has now overseen the destruction of a Lois and a Superman, reducing this universe's number of each from two back to the normal one. Looking like the similarly-robed character Destiny, he seems to be trying to orchestrate things on a grand level. Perhaps he really is Ozymandias and is playing against his erstwhile antagonist Dr. Manhattan as the two of them warp reality in the current DC Universe – That would certainly be, as Superman says, "something bigger."
