Light Yagami's actions in Death Note have a profound impact on the themes of justice and morality. Initially, Light believes he is serving justice by eliminating criminals with the Death Note, but as he becomes more power-hungry and manipulative, his actions blur the lines between justice and vengeance. This challenges the audience to question the morality of his methods and ponder the consequences of vigilante justice. As the series progresses, Light's descent into moral ambiguity highlights the complexities of ethical decision-making and the dangers of absolute power corrupting one's sense of right and wrong. Ultimately, Light's actions serve as a cautionary tale about the consequences of pursuing justice through immoral means.