Warning! Spoilers ahead for Future State: Justice League #1
DC’s future Justice League already have their hands full in Future State. In only the first issue, both the League and their rivals, the Legion of Doom, were easily defeated by the powerful supervillain team known as the Hyperclan.
The Hyperclan first appeared in JLA #1 by Grant Morrison back in 1997, and while they may not be DC’s most famous band of villains, they are still incredibly dangerous.
The Hyperclan are White Martians, a separate, more aggressive race than the Green Martians like J'onn J'onzz. Being Martians, the members of the Hyperclan have all the same powers as Martian Manhunter, including super strength, heat vision, telepathy, and a wide array of other powers, but their ability to shape-shift is perhaps their most important. When the Hyperclan first came to Earth, they masqueraded as a team of superheroes sent to protect the planet, with the ulterior motive of replacing the Justice League and conquering the world. The Hyperclan’s plot was ultimately foiled in JLA #4 and they haven’t been seen since - until now.
Future State: Justice League #1 by Joshua Williamson begins with the League investigating the apparent death of the Legion of Doom, who were killed off almost as soon as they were introduced. With no clear culprits in sight, the League disperses, but Green Lantern Jo Mullein stays behind to continue the investigation, and she comes to a startling conclusion: the only ones powerful enough to murder the Legion are... the Justice League. Almost as soon as Jo puts the pieces together, the members of the League are attacked and subdued by doppelgängers of their teammates, who are then revealed to be the Hyperclan in disguise. “When we first came here, we made a mistake,” Protex, their leader, says, “We tried to rule in these forms…The Justice League revealed us as white martians right away. So this time…We will be the Justice League.”
Based on this, it looks like the Justice League is essentially facing their version of Marvel's Secret Invasion. After their previous failure, the Hyperclan knows that the people of Earth will never accept a new, unknown team of heroes over the Justice League, so if you can’t beat them, become them. The new Justice League may have a few victories under their belt, but they still lack the experience and synergy of the original team, making it all too easy for the Hyperclan to take them down one by one. With the heroes incapacitated, the martians can easily assume their forms and take their place, bringing them one step closer to world domination
Killing the Legion of Doom right off the bat shows that the Hyperclan means business, and they're strong enough to make taking down the Justice League look like a piece of cake. Why they kept the heroes alive is anyone’s guess, but it's a decision they’ll likely come to regret.