Light Yagami navigates the complex moral and ethical dilemmas presented by his role as Kira by justifying his actions through a belief in creating a better world by eliminating criminals. He convinces himself that he is a righteous judge and savior of society, leading him to rationalize his morally questionable decisions. Additionally, Light's intelligence and strategic thinking enable him to manipulate situations to maintain control and justify his actions as necessary for the greater good.
