Jerome and Jeremiah Valeska
When The Penguin tries to convince Scarecrow and Mad Hatter not to go through with Jerome’s plan, they lock him in the Blimp. In the meantime, Jerome attacks Gotham City and Captain Gordon fights him and Jerome loses and falls to his death but he warns that what he did is just the beginning. The Penguin escapes and steers the blimp out of Gotham City. But Jerome realized that that might happen so he sent Jeremiah his insanity gas turning  Jeremiah’s skin white and making him a psychopath. Jeremiah then tries to convince his friend Bruce Wayne to help him destroy Gotham City and when Bruce doesn’t, Jeremiah uses Jerome’s cult to try to kill Bruce. And when that doesn’t work, Jeremiah teams up with Ra’s al-Ghul, stabs Bruce’s girlfriend Selina Kyle, destroys every bridge out of Gotham City with bombs and shuts down all electricity in Gotham City. The police then abandon Gotham except Captain Gordon and some others and criminals take over the city.