WARNING: The following contains spoilers for Dark Nights: Death Metal #4 by Scott Snyder, Greg Capullo, Jonathan Glapion & FCO Plascencia, on sale now
The actions of the Darkest Knight have broken the multiverse in many unexpected ways, introducing various demented and dark versions of classic DC characters. One major cosmic villain, in particular, has reached his apex form in the event.
Revealed to be the true Darkseid, the victorious New God in Dark Nights: Death Metal is the ultimate evolution of Darkseid -- and he still has dark designs for Superman.
After his final battle with his son Orion in Final Crisis, Darkseid fell to Earth -- causing a rift in the universe itself. While on Earth, Darkseid and his agents went about weakening the planet enough so that it could all fall under the thrall of the Anti-Life Equation. While he succeeded for a time -- with most of humanity becoming an extension of his will and a mind-controlled Wonder Woman serving as his chief hunter -- the heroes were eventually able to overcome his plans and destroy his physical form. However, Superman and a collection of other multiversal heroes were needed to destroy his essence, leading to a final battle with the second threat of the event, Mandrakk the Dark Monitor.
However, this version of Final Crisis didn't end so well for the heroes. It is one of the three realities created to produce Crisis-level energy. In fact, it appears that the major divergence was the attempt to bring down Darkseid's body, meaning it came down to Barry Allen and Wally West failing to bring the Black Racer to Darkseid. Instead, Darkseid extended his control over the remaining heroes and transformed the world into his image, becoming even stornger as the years passed. Even the multiversal armies of Supermen weren't able to stand up to Darkseid, leading to the dark New God having an entire army.
As Darkseid reveals to the core-universe Superman, he is in fact the core-Darkseid, taking advantage of the Darkest Knight to achieve his final form. He has become taller and more destructive, growing large stone tusks and developing a mane of white hair. His army includes the last of this world's heroes and their multiversal counterparts, broken into his service. Supergirl and Batgirl hang by his side, while Green Lantern uses his ring solely to create a throne for Darkseid to sit upon. While Superman may only perceive Darkseid's time on Earth as months, Darkseid has lived for eons from his perspective with his own universe conquered, completing his evolution from a New God into an Old God.
But Darkseid has one more plan, and it requires Superman. He's turned much of the Earth into a fire-pit like Apokolips, and he intends to throw Superman into one of them. This will overwhelm Superman and complete his transformation into a being like Darkseid. Ever since he escaped from the Batman/Darkseid fusion known as High-Father, Superman has been trying to keep his cells from succumbing to his injuries, as each dead one brings him one step closer to becoming like Darkseid. But the fires are too much, and Darkseid ignores each of Superman's desperate pleas. Instead, the Kryptonian hero is lowered into the flames and is consumed.
When he rises, Superman's skin appears as cracked rock, suggesting his transformation into Darkseid's "Final Son" is complete. Luckily for Superman (and pretty much every reality and the multiverse), this is quickly reversed when Wonder Woman succeeds at getting through to Superboy-Prime and convincing him to turn against the Darkest Knight. A Darkseid-corrupted Superman could bring down entire universes on his own, spreading the edicts of the Anti-Life Equation with him. It's also a reminder of the threat posed if Superman was to kill in the coming battle, as his Darkseid infection still seems to exist -- and could corrupt Superman if given the chance.