WARNING: The following contains spoilers for Action Comics #1038, on sale now from DC Comics.
Superman faced a defeat more devastating than Doomsday in Action Comics #1037. When his new team, the Authority, finally reached Warworld to free everyone enslaved there, they faced an opposition unlike anything they had ever faced. The consequences of underestimating Warworld's leader, Mongul, were defeat and, for some, death. While the Man of Steel himself was brought to the brink of death at the issue's climax, he revealed in this latest installment that his absolute defeat was really... a good thing?
With the Authority in ruins, a powerless Superman was thrown in with the rest of Mongul's slaves in Action Comics #1038 (by Phillip Kennedy Johnson, Miguel Mendoça, Adriano Lucas, and Dave Sharpe). When Midnighter, the only member of the team who managed to escape capture, came to rescue him, he was outraged to discover that the Man of Steel didn't want to be saved. He didn't even want to take down Warworld.
Superman explains that, although they clearly went through an unexpectedly catastrophic defeat, this situation is the best thing he could have asked for. Now that he's amongst Mongul's slaves, he can reach them where they are. He's aware that there was always a flaw in his plan. If he simply freed the slaves with the help of the Authority, they wouldn't truly be free of their ruler. They would be free of Mongul physically, true, but they would still be fiercely loyal to him and want to be slaves. Now that he's amongst those who believe the despotic dictator's twisted lies, he can work on getting them to believe in his truth instead of their evil ruler's.
This is an example of Superman using his real power. Though most focus on the hero's incredible abilities of strength, speed, flight and everything else in between, that's not why he's endured all these years. It's also not why the whole DC Universe respects this larger-than-life figure. Superman's real power is the way he gets people to believe in him. He's not just about truth, justice and a better world, one of his core beliefs is hope. This has spread right throughout the DCU. Not just to Earth but to the universe beyond. He even inspires a thousand years in the future, as he's the reason why the Legion of Superheroes originally formed.
This innate ability to make others believe in him and create hope where there is none is already spreading across Warworld. He's barely been a prisoner a day and yet Mongul's loyal warriors are already starting to draw his symbol and have recognized it as a beacon of hope.
Midnighter, however, isn't convinced. Superman may be where he wanted to be but he brought a whole team with him. Thanks to his recklessness, Lia Nelson is dead and Apollo will soon be next. It's clear that Midnighter thought he had signed on for a very different kind of mission. His plan here was to free the Man of Steel, along with the rest of the Authority, and destroy Warworld completely. Seeing that the slaves don't want to be freed, he believes it's ok to let them die. This may be a cruel outlook but he does have a point about Superman seemingly valuing those who hate him over his own teammates, who have literally died for him.
However, Superman being Superman, he has an answer even to these valid doubts. He doesn't value the lives of these slaves over the lives of his teammates. He values them both equally. Midnighter may see this as the Man of Steel abandoning his team but that isn't true. He truly believes that he can free Warworld's slaves and his team, all whilst dismantling Mongul's rule. If it were anyone else, this would be impossible. For Superman though, it just might come true.