Justice League's current arc finds the team in danger of losing the very concept of existence as they know it. With Lex Luthor kidnapping Perpetua, the creator of DC's last Multiverse, and about to unleash doom on the current reality, the heroes journeyed into the mysterious Sixth Dimension to learn how to avert the impending crisis.
However, they found a paradise instead; a potential future every single one of them dreamt of at some point. But, as we know, such utopias are too good to be true, and Issue #21 finally reveals the dangerous secret of this one courtesy of the regal Superman, whose true identity is tied to one of DC's darkest events ever.
After falling in love with this reality, the League finds themselves abruptly summoned by Martian Manhunter to their telepathic boardroom. There, they're told that everything is a facade, but Flash and Green Lantern are too stubborn to believe him; after all, they've seen how their future counterparts are helping to ensure this is the perfect reality. Even Wonder Woman doesn't believe they're in a trap, having previously been swindled by an idealistic version of Themyscira.
Surprising everyone, considering they've convened in a telepathic "room," the older Superman arrives to allay everyone's fears in an unusual fashion. He straight-up admits that this future is not quite what it seems -- it's the Multiverse these heroes could have, but only if they agree to abide by his plan. To buy their trust, this entity took on Superman's form, but now that the cat's out the bag and it's decision time, he unmasks as his true self: The World Forger from Dark Nights: Metal.
He offers the League a choice: Buy into his vision, and he will replace their dying Multiverse with this nigh-perfect reality. This is the only one, he claims, that Lex hasn't damned, the only one where hope pays off. But there's a twist that the League will have to accept; in order to bring this Multiverse life, one member of the League -- hinted to be Batman -- will devise a predictive tool a la Minority Report that would allow the heroes to sweep through the cosmos, raid planets and preemptively imprison those who stand on the side of evil. The upside is that those who believe in justice would be free to live as they want, thus giving birth to the paradise they've all been experiencing.
This is the first time we're seeing the Forger make a big play like this. In Metal we were only told of him in flashbacks, but now, reconciling all the details, we know his full story. He was Perpetua's firstborn, the brother to the Monitor and Anti-Monitor, and the one who imprisoned his mother when she got out of control. He created Multiverses in the wake of this, and those that were unstable he ordered Barbatos (the bat-dragon) to eat in order to recycle their power to the Forge. When Barbatos betrayed and killed the Forger, the Dark Multiverse encroached on the DCU, thus giving rise to Metal.
As it stands, we don't know how the Forger survived that clash with Barbatos, or why he's asking permission to enact this plan rather than simply doing so. Shockingly, Batman trusts him, saying that after eons of creating Multiverses, watching them rise and then fall, the Forger, whether the League would like to admit it or not, is really the best choice to "hammer and shape" the future.
The Forger does seem to stand on the side of justice, and it obviously pains him having to execute such a harsh plan, but ultimately, he knows there must be sacrifice for the greater good to prevail. As a collective, the League doesn't vote to go along with this philosophy, but with the Dark Knight already torn internally, the Forger may be one step closer to fulfilling his endgame.