 Kumararaja finalised Guru Somasundaram for the character of Kaalayan, after he had seen him performing the titular character in Koothu-P-Pattarai's play "Chandrahari".Kumararaja had stated that the voice modulation and pattern of the Kaalaiyan character was based on Somasundaram's performance in the play Chandrahari, which eventually resulted in casting him in the film.Somasundaram cited that the dialogues were also written "keeping the artist in mind".