Vikram’s character in Deiva Thirumagal is mentally challenged. Sean Penn and Shah Rukh Khan did similar roles in recent times and Penn was even nominated for an academy award on the strength of his performance in I Am Sam. Vikram therefore wanted to do something special with the character and give it his own interpretation.
As preparation for the role, he spent about two months researching the character and visited various institutions, spending time with the patients in order to study their mannerisms and to understand what they are dealing with. It became a habit with him to spend hours at Pathway (one such institution for afflicted individuals) deriving insight into their condition and to make his portrayal sensitive.
Amala Paul was impressed seeing the actor at work. Compared to Vikram, she is a beginner so she made sure to learn everything about acting from the national award winner. After Myna, this film required a mature performance and Amala Paul really gave it her all. Everyone on the sets were impressed and declared that she had really come into her own as a good actress.