Warning: SPOILERS for Green Lanterns #54.

When Superman imprisoned the Cyborg Superman in the Fortress of Solitude, he didn't expect Hank Henshaw to take over the Kryptonian technology within - and definitely not use it to take control of the Green Lanterns' Central Power Battery on Oa.

The last few issues of Dan Jurgens's Green Lanterns have seen the Green Lantern power rings out of control. A dark force has been manipulating the Corps, murdering Guardians and turning members against one another. Last month's Green Lanterns #53 came to a close with Simon Baz heading to the Fortress of Solitude, believing he was coming to rescue a trapped Superman.

The final panel revealed he was instead about to free the Cyborg Superman... the secret cause of the Corps' misfortune.

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Although Superman had locked Henshaw in a comatose state, his mind had invaded the technology holding him prisoner. Using the Kryptonian tech nearby to reach out with his consciousness, Henshaw ultimately found his way to the Green Lanterns' Central Power Battery. There, he acted as a virus: every time a Green Lantern recharged their ring, Cyborg Superman was able to infect it and take control.

Worse still, freedom wasn't Cyborg Superman's only goal. He's managed to secretly manipulate the unwitting Baz into bringing him the Phantom Ring - a legendary Power Ring with which he can master the entire emotional spectrum.

By issue's end, Cyborg Superman has just become one of the most dangerous threats the Green Lantern Corps has ever faced. He's armed with the Phantom Ring, one of the most powerful rings ever created by the Guardians. Even worse, the Green Lanterns trust their rings implicitly, and through them, Henshaw can instruct the Green Lanterns to do anything he wants. Should a Green Lantern resist, he can simply tell their ring to stop obeying the user's orders.

But there is one flaw in Hank Henshaw's plan - a flaw by the name of Hal Jordan. Jordan created his own Green Lantern ring from pure willpower, and he doesn't charge it through the Central Power Battery. That means Hal Jordan - alone of all the Green Lanterns - will be able to resist the Cyborg Superman.

There's been a curious amount of overlap between the various Green Lantern and Superman comics recently, with Henshaw only the latest major Man of Steel villain to appear in the cosmic storyline. General Zod founded a new Krypton in defiance of the Guardians of the Universe's edicts. But this time around, the stakes are higher than they've ever been before. In order to orchestrate his freedom, Cyborg Superman has already brought one race to the brink of extinction due to mistakes he manipulated the Green Lanterns into making.

Now he's free... leaving fans to wonder just how much damage he will inflict to the Corps, the galaxy, and the DC Universe before he's finished.

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Green Lanterns #54 is available now from DC Comics.