The Legion of Doom is a group of supervillains which acts as the main antagonist faction of the animated movie Justice League: Doom.
The Legion of Doom is assembled by Vandal Savage. Savage invites them into his secret headquarter at a swamp where he tells them that he will pay them 100.000.000$ plus expenses for every member of the Justice League they manage to kill. He also implies that the destruction of the Justice League would bring in much more money for him and claims that every member of the League can share in.
After joining the League, Bane sets out to kill Batman. After being told what Batman's secret identity is, he visits Wayne Manor where he digs out the coffins of Thomas and Martha Wayne. Posing as a concerned citizen, Bane calls Wayne Manor and Bruce immediately rushes to the Manor graveyard. When Bruce rushes towards the graves, Bane puts on his mask and activates the drains pumping Venom into his body. Now powered up, Bane kicks Bruce into one of the empty graves. When Bruce attempts to climb out, Bane beats him savagely. When he drops Bruce Bruce shows no sign of defeat. He only demands to know what Bane did with his parents' bodies. Bane merely replies that when they fought before, Bane broke the Bat. He tells Bruce that this time, he will break the man. He then stomps into Bruce's face. knocking him out. When Bruce regains consciousness, he hears a voice message from Bane who reveals that he has left to collect his payment for dealing with Batman. While looking around, Bruce realises that he has been buried alive with the corpses of his parents.
Ma'alefa'ak attacks Martian Manhunter by posing as a seductive woman in a bar. Martian Manhunter thinks that she looks familiar but cannot really recognize her. Only when Ma'alefa'ak urges him to use his Martian vision, Martian Manhunter recognizes him. When Martian Manhunter asks what Ma'alefa'ak wants, Ma'alefa'ak reveals to him that the drink he bought him was laced with poison. Ma'alefa'ak reveals to him that while the poison will not kill him, he will sweat it out again. Ma'alefa'ak reveals that the poison is inflammable. Ma'alefa'ak then throws a lighter at Martian Manhunter who is immediately set afire. While Martian's friends attempt to extinguish him, Ma'alefa'ak leaves the bar. Due to the poison in his system, he cannot be extinguished and continues burning even after he jumps into a river.
Cheetah flat-out attacks Wonder Woman on a ship at the harbor. She manages to slice Wonder Woman's arm with her claws and thereby drugs her. Wonder Woman hallucinates multiple Cheetah's standing all around her. She leaves Wonder Woman alone to fight these hallucinations. In truth, the hallucinations are SWAT officers who Wonder Woman believes to be enemies.
Mirror Master lures Barry in by robbing a cash transport by train. Barry enters the train, untying three security guards. In the next train-part, Barry is confronted by Mirror Master who confuses him by creating holograms of himself. Venturing in the next part, Barry finds that Mirror Master has an unconscious, elderly woman in what he calls his 'hostage-box'. He reveals that the box will blow up at the end of a countdown, killing the old woman unless Barry manages to save her with his super speed. Barry senses a trap but Mirror Master tells him that he has no chance but to take the risk. While trying to disarm the box, a device is drilled through Barry's arm. Mirror Master tells him that the device contains a bomb with a three mile blastradius. He also tells him that the bomb will explode should Barry attempt to remove. However, the bomb will also explode should Barry do nothing. Mirror Master warns Barry that once Barry has started running, the bomb will explode should he decelerate. Before Barry can leave, Mirror Master reveals that he too was only a hologram.
Green Lantern is called to a hostage situation at a salt mine. Inside, he is attacked by the Insight-Brotherhood who he defeats without much problems. After saving the workers who have been taken hostage, one of the remaining Brotherhood-members kills a female hostage. Green Lantern is devastated and cradles the woman's body when the same woman walks towards him from afar. The woman taunts Green Lantern for his failure before revealing herself to be Star Sapphire. She tries to talk him into removing his ring which Hal does. Sapphire then disappears, leaving a sobbing, broken Hal Jordan behind. It is later revealed that all the attackers and hostages were androids and used by Sapphire to break Hal.
Metallo disguises himself as a man attempting to commit suicide. Superman is called to the scene and seemingly manages to talk the man out of shooting himself. The man then shoots Superman in the stomach, revealing that the projectile was a kryptonite bullet. He then transforms into Metallo and opens a lid in his chest, showing his kryptonite heart. Weakened from the glow and the bullet, Superman stumbles backwards and falls off the building, crashing into the pavement below.
After each member has succeeded to take down his rival, they meet back at the Hall of Doom to celebrate their victory. Savage tells them that they have succeeded in their mission but also claims that they can join in in his next plan. He warns them however that this plan is genocidal as he attempts to kill at least half of the worlds population. He then tells the Legion his backstory and how he became immortal. Cheetah does not believe him and Savage allows her to slice his throat. After falling to the ground seemingly dead, Savage gets back up. Savage then reveals to his Legion that he plans do destroy so much as to have the surviving men gather around him as the worlds new leader. He offers the Legion dominion over the world that remains - second only to Savage himself. They all agree with his plans.
After Batman, who has saved himself, Cyborg and Wonder Woman save the remaining members of the League, Batman reveals to them that the plans to take out the Justice League were made by him should one or more of the members go rogue. Unbeknownst to him, the plans had been stolen from the Batcomputer by Mirror Master, who had infiltrated the Batcave earlier. Mirror Master was not aware that the plans were unlethal however, which allowed the League to survive. The League watches surveillance footage from the night Mirror Master snuck in and track him down to the Hall of Doom.
At the Hall, Savae reveals to the Legion that he plans to destroy the sunward facing side of the earth with a solar flare, killing half of the population but also destroying advanced technology, allowing the Legion to reign supreme. They are interrupted by the Justice League who reveal themselves to the Legion. In the resulting battle, each hero fights his respective villain. Although the situation at first seems dire for all the heroes, they manage to prevail. Meanwhile Cyborg manages to abort the missile launch but is then stabbed in the back by Vandal Savage who kicks him down the abyss. He restarts the countdown but is attacked in turn by Cyborg. After fending him off, Savage immediately launches the rocket. The rockets burst ignites Ma'alefa'ak, killing him. At the same time, Batman manages to cut Bane's Venom supply, Superman beheads Metallo with his laser vision and Flash knocks out Mirror Master. Green Lantern overcomes Sapphire's power and smashes her into a wall, removing the crystal from her body and rendering her normal while Wonder Woman defeats Cheetah.
Although Superman destroys most of the rocket, he misses one of the sub-rockets. Savage manages to create the solar flare he intended. While watching his success, Savage is knocked out by Wonder Woman and Cyborg. Realising that the Legion must somehow have had plans to survive the flare, the Justice League enhances the mechanism and thus foils Savage's plans after all. This also causes the destruction of the Hall of Doom which Superman lifted into otbit in order to save earth. This ultimately destroys the Legion of Doom, whose surviving members are arrested. Savage is found guilty for crimes against humanity and sentenced to life in prison.