In this story, Roman Sionis is on the line between following and breaking the law. He has lasted long in the busy city of Gotham, but he hasn't achieved worthwhile success. Roman wishes to partner with Wayne Enterprises to perhaps develop certain products together and reach a mutual payout. After Bruce Wayne disagrees with his plan, Roman becomes enraged with determination and begins taking chances on products to get money as quickly as possible. However, a facial product that disfigures one's face makes it through the manufacturers, and Roman is in an even tighter spot.  Enraged by his past (his family's horrendous use of him) and his supposed friend Bruce Wayne's treatment of him, Roman decides to adopt a mask that will cover his darkest action: kidnapping Bruce Wayne and convincing him to work for Sionis. It is Roman's goal, especially once Black Mask is created, to partner with Wayne Enterprises and gain a profit by any means necessary.

No live-action proxy, so give me your interpretations.

Roman is more or less calm. He comes across as desperate. He's not overly panicky, but he does want to be accepted, economically and personally. However, once his situation starts getting bad, Sionis will start to sound much more like his masked counterpart.

For Black Mask, go wild. Really. Black Mask is a pretty vicious character. He has spurts of wild rage and irritated contempt. His voice is less gravel-like than Deathstroke's, and he has much more rage hidden beneath it. He's not always yelling, but there is certainly some pent-up anger issues lurking beneath that mask of his.