Dark Knights

The Dark Knights are a group of supervillains in the DC Comics universe. They are evil and twisted versions of Batman from destroyed Earths who are saved and united by The Batman Who Laughs in order to carry out Barbatos' goal of bringing darkness throughout the multiverse. This has subsequently made them enemies of Batman and the Justice League. Their first appearance was in Dark Days: The Casting #1.

History
The Dark Knights make their appearance when their leader, The Batman Who Laughs, is ordered by Barbatos to find other evil and twisted versions of Batman from the Dark Multiverse who are trying to keep their own Earths from being destroyed. He succeeds and is able to save a group of them moments before their Earths are annihilated. Those who were saved are The Drowned, The Dawnbreaker, The Merciless, The Devastator, The Murder Machine and The Red Death. The Dark Knights arrive on Prime Earth after the Court of Owls ambushed Batman, Superman, Wonder Woman and a baby Darkseid and use the last type of metal required for the Mantling to turn Batman into a doorway for Barbatos and the Dark Knights to enter the Multiverse. Barbatos then has his Dark Knights kill the Court of Owls before he personally drains Superman and Wonder Woman's life force and are incapacitated.

After they arrived, the group of supervillains take control over the homes of the Justice League and eventually seized the Watchtower. They later are about to battle the Gotham Resistance in Gotham but are taken away by Doctor Fate before any casualties on either side can occur. The Dark Knights would confront Superman and Wonder Woman after they escaped from Barbatos's conduit tower that is stationed in Metropolis. The Devastator attacked Superman but was prevented from doing any serious damage to him through the intervention of The Flash and Doctor Fate. Once the superheroes on Prime Earth reveal their location to the Dark Knights, they immediately launch an offensive attack at the Oblivion Bar and killed Nightmaster in the process.

While the Oblivion Bar is burning, The Batman Who Laughs gets Dawnbreaker to play a song on the jukebox and works despite it's on fire. As they are listening to the song, Superman breaks the barrier between the Phantom Zone and the Dark Multiverse, confident Kendra was wrong about it being a trap. When he takes stock of his surroundings, he sees a dark tower shaped like an S, in which Superman realizes at that point it was a trap. Then, three decrepit Supermen subdue him, and he hears someone ask him why he came which is then revealed to be Batman, who is almost completely drained of life. Superman explains that he got his message, but Batman reveals that the message he picked up was Barbatos deceiving him all along. The real message from him was actually hidden in the song from his last vision. The notes from the song "the Super Sons" played were ordered in the reverse of his emergency code as a warning not to come for him. As The Batman Who Laughs toasts over Superman's defeat, it's revealed that the final component needed to complete Barbatos' plan was the energy stored in Superman's cells. As Batman becomes engulfed in dark energy, he states that Barbatos was right about everything leading back to him in the first place, and that everything will now be submerged into total darkness.