Just for the record, this is a DC universe parallel to the Injustice universe. Disclaimer: I own nothing.
Superman watched as all of Metropolis went up in flames. He had tears pouring down his face. The rest of the Justice League tried to comfort him. '"Lois… my son…Metropolis…" he muttered. He flies toward Arkham. A few minutes later, Superman has Joker by the throat and was ready to punch a hole through his chest. But that's when he heard her. Lois.
"Clark..." His hand lowered slightly. "Don't do this. You are a hero, Clark. Heroes don't kill. I understand why you want to kill him, but think about your friends, what would they say about this? Just put your hand down, Clark. Just stop. Be the hero you are meant to be. And remember, even in death, we are with you." He turned around and saw, not just Batman, but everyone else who cares about him, his friends his family, everyone. They all said the same thing, "Stand down." He dropped the Joker, fell to his knees with tears pouring down his face like raindrops on glass. Batman walked over and put his hand on his shoulder.
A few days later the Joker was in World Court awaiting a verdict. "Joker," the chief Judge said, "a vote has been taken, and it is unanimous. You are hereby guilty of violating every crime known to man. You are hereby sentenced to death. Give him the chair." A while later the heroes of the world watched as the Joker was strapped into the electric chair. The guard pulled the lever and the Joker was electrocuted to death. Batman took his remains back to Gotham where he burned Joker's body. A few weeks later at the Hall of Justice, Amanda Waller is discussing with the Justice League a new protocol for Meta-Humans. Superman, Batman, Wonder Woman, Green Lantern, Flash, Aquaman, Martian Manhunter, Cyborg, Shazam, Green Arrow, Black Canary, and Hawkgirl sit in their chairs.
"Ladies," Amanda said, "gentlemen, while a great many of the people of the world see you as heroes, there are some who would use the word vigilante. You have operated with unlimited power and zero supervision. This was something we were willing to tolerate until Metropolis." She hands some paperwork to Superman. "The United Nations has voted on whether or not Meta-Humans should be regulated. Only 15 stand against it. They all it the Meta-Human Registration Act. It will make the Justice League a U.N. organization and as such, you will only be allowed to be called to action, when and if it is deemed necessary."
"By that logic, you ask us to sign away our free will." Batman stated. "I am sorry Amanda, but what if someone was attempting to kill someone while I was watching, and I had a choice to help them, I would. Regardless of what your bureaucrat friends say. I will not sign."
"I will." Superman said. "I was forced to kill Lois Lane and my unborn child, and destroy Metropolis. If they told me not to go, they could've stopped me from making the biggest mistake of my life."
"Fine." Batman said. "Let us take a vote. Wonder Woman?"
"I'll sign." Wonder Woman replied.
"Green Lantern? Flash?"
"I'll sign." Green Lantern said.
"I am sorry but I cannot." Flash said.
"Aquaman?" Batman said.
"If it protects Atlantis, I will sign." Aquaman replied.
"Martian Manhunter? Cyborg? Green Arrow?"
"I will sign." Martian Manhunter said.
"I am going to have to side with Batman on this." Cyborg said.
"Same here." Green Arrow agreed.
"Shazam? Black Canary? Hawkgirl?" Batman said.
"Freedom is more important than security. I am going to have to say no." Shazam said.
"I am going to have to agree with you on that." Black Canary said.
"I choose to side with Superman." Hawkgirl said.
"So that is six for the Meta-Human Registration Act, and six against. Dead tie."
"Ties are not acceptable." Amanda said. "Superman, Wonder Woman, Green Lantern, Aquaman, Martian Manhunter, Hawkgirl, you will remain heroes on the Justice League. Batman, Flash, Cyborg, Green Arrow, Black Canary, Shazam, you are going to have to retire."
"And if we refuse?" Batman asked.
"You will all be arrested. You will always have the option to register." Amanda leaves.
Meanwhile, in Athens, Greece, a man accidentally crashes into a car in a driveway. He knocks on the door. "Excuse me," The man said, "I am sorry, I jumped the curb. I just… look maybe we can work something out. My name is Patrick Morgan. I was just visiting from the U.K. Look can't we have a drink?" A Greek man opens the door, and Patrick grabs hold of him and strangles him. Patrick then changes into a sort of ancient Greek armor. "I apologize. My true name, I am Ares. And this is only the beginning."