Sarjun's Airaa, starring Nayanthara in the lead role, has a butterfly playing an important role throughout. In addition, the film is a case study on butterfly effect, which means a small, harmless incident can turn into something really big. It has all the banalities of a horror film - there is a bungalow in a place outside the town (Pollachi), there is a spirit inside the house with a motive, there is a flashback portion explaining the past of the spirit. However, the flashback portion is filled with harsh realities - the director goes about addressing multiple issues such as racism, female infanticide and so on.

Kalaiarasan as Amudhan delivers a calm and composed performance. While the flashback portions are written with a lot of maturity, the characters -  young Bhavani (Gabrella Sellus), and young Amudhan (Maathevan) deliver splendid performances. Their looks breed innocence and their romantic portions are genuinely beautiful. Nayanthara sheds her Lady Superstar tag while playing the elder version of the naive Bhavani, and looks totally contrast to Yamuna. Sadly, Yogi Babu's comedy doesn't offer any hilarious moments that is expected out of him.

A lot has to be said about Sundaramurthy's music. In a specific scene in the opening sequence, when two policemen are on a run, you just hear a monotonous beat in the background, but the tempo keeps shifting according to the pace with which they move, in sync with their heartbeats. Even visually, there is always a sense of eerie and impending doom because of the reddish tone used throughout.

The film is written by Priyanka, who has given us full-fledged character arcs for Yamuna, Bhavani, and Amudhan. There is a clear motive behind each character's actions, which is what makes the writing clean. With a female writer on board, the female characters, in particular, are well defined. They are not women from Venus and Mars who are in privileged positions, preaching what feminism is. Instead, they are women we meet every day, bound by society's definition of what is right and what is wrong.

The first half has two parallel story tracks, where incidents take place, but we are not shown the reasons, leaving us clueless. The camera movement and smooth editing also work in tandem to create that sense of confusion. Sudharshan Srinivasan, the cinematographer must be credited for the usage of the inverted angles and the swirling shots. On the weaker side, this confusion can also create a sense of detachment with the film, and you could lose track.

As mentioned in the first line, there is clever, extensive usage of a butterfly, which also ends up as a metaphor. In fact, in the last shot of the film, the butterfly that has been restless throughout, becomes calm and composed. There is another metaphor with a lift door, that explains why Bhavani the Spirit wants to kill people. The issue here is that the motive doesn't sound convincing enough and that might be a major concern for the audiences. In a classic Cause vs Effect tale, the effect looks like Airaa-vat elephant, while the cause looks like a rat in front of it. Though it is real, it does not offer the story a realistic closure. Overall Airaa falls just short of an exciting package, due to a less convincing climax.