YMMV / Justice League S 1 E 1 To 3 Secret Origins

• Complete Monster: The Imperium is the one behind the genocide of the Martian race. A being that craves lifeless darkness, the Imperium targeted the Martian civilization years ago to conquer Mars and annihilated nearly all life on the planet, leaving J'onn J'onzz as the only survivor. Years later, after being unsealed from a forced stasis, the Imperium sets up plans to repeat the process on Earth and destroy the human race, having its henchman Kill and Replace an astronaut in a plot to disable humanity's nuclear defense systems. A sadist and a coward on top of this, the Imperium gleefully tries to torture J'onn to death when it realizes J'onn is the last Martian, and when its plans go awry, it leaves all of its own loyal soldiers to die, even swatting away its henchman to burn to death in the sunlight.
• Like You Would Really Do It: When Diana and J’onn J’onzz hear Batman being taken down off-screen, J’onn tells Diana that the villains killed Batman. But of course, Batman is actually alive and J’onn not only knew it, but used his telepathic powers to conceal the truth from everyone else!