Roman Sionis is an extremely broken character. So broken that he believes Gotham is better in the corrupt state it's in. As a child, during what was named "The Gotham Massacre", his house was attacked and burned down by a rioter. His parents died, his half-brother Harvey left him in the fire to die, and his whole face ended up getting burned before he could make it out. He became obsessed with masks as a way to hide what Gotham did to him. He takes revenge back on the city by simply letting it kill itself. He doesn't have many lines in this first episode, but he will definitely have more to do later in the show.