 He added that in "formulaic Tamil films", the protagonist would require a flashback to show a reason to fight evil or that the "hero would wait for the villain to make the first move", but noted that "Thani Oruvan" would eschew those typical notions seen in Tamil films.He considered several actors for the lead role but finally chose Jayam Ravi again as he wanted an actor "who would trust him blindly" because he had wanted the film to be a "career-changing film".After unsuccessful negotiations with Arya and Madhavan, Raja cast Arvind Swamy in the role of the main antagonist because he wanted "an actor whose attractiveness would act as a distraction from his evilness".