After exiting battle, The Joker reloads his gun with enhanced bullets so that his next normal attack deals an additional 200 (+165) physical damage and has an increased range. The enhanced bullets also reduce the target's movement speed by 90% for 1.5 seconds.
The Joker reloads his clips with enhanced bullets once he exits a fight. Use these enhanced attacks wisely to deal additional damage at key moments. Increase the hit rate of The Killing Joke by hitting enemies with Punch Line first to reduce their movement speed.
The Joker's origins are shrouded in mystery, but what is known is that he was once a small-time criminal who, after a freak accident, transformed into the Clown Prince of Crime. The Joker's belief that life can change at any moment drives his thirst for chaos, which has fueled his reign of terror in Gotham City. Believing that life is nothing more than a cosmic joke, the Joker has dedicated himself to showing others—the whole world, even—that in one moment, your whole life can get turned upside down.
The Joker has kidnapped, crippled, maimed, murdered, and tortured countless individuals throughout the world, but his locus of operations is Gotham City. Or, it was. In Gotham, the Joker was obsessed with the punchline to his best joke: the destruction of Batman's ideals. Yet, try as he might, no matter how agonizing nor how elaborate the situation, Batman refused to give in to the Joker's games. Even after the Joker's actions cost Batman some of his dearest allies, the Dark Knight would not break. Instead, Batman turned the tables on the Joker by utilizing a highly modified version of Scarecrow's fear toxin.
Prior to this moment, the Joker had never truly tasted fear. With Batman's altered fear toxin sluicing through his veins, the Joker was terrified for the first time. The traumatic nature of the experience was enough to unmoor the last fastenings of the Joker's sanity. Rather than stand trial for his crimes, he was committed to Arkham Asylum. Here, the Joker was a comedian without a joke. What could be truly funny in the face of true terror? The Joker began to despair that he might never laugh at the world ever again.
That changed when a new inmate was brought into Arkham. This man, too, was mad, but in between his demented ravings he spouted lucid streams of mathematical equations and whispered incantations in hushed tones. And when he would sleep, a single phrase was on his lips: Athanor… Athanor. The man's madness intrigued the Joker. With some charm and deception Joker befriended the inmate and learned of where the man had come from. A scientist in a former life, the Arkham inmate had studied radiation spikes across the world that coincided with paranormal phenomena. The scientist had found the answer to these riddles: a portal to another world.
The scientist spoke of this realm, Athanor, with reverent tones. It was clear that the experience had changed the scientist profoundly. The Joker was not in search of spiritual enlightenment or an experience that would cure his madness; no, he longed to see this world of beauty and order, so that he might make a grand joke of it. With his mind finally resolved to a productive endeavor, the Joker escaped Arkham, as he had so many times before. This time, instead of wreaking havoc upon Gotham, the newly freed Joker made for Athanor.
After months of searching, the Joker finally found the portal to Athanor. And now, even the gods who contend to rule that realm will have to wrestle with the man who is chaos personified.