In "Death Note," the protagonist, Light Yagami, initially believes he is sacrificing his own moral compass in order to rid the world of criminals and create a better society. He justifies his actions by convincing himself that the end justifies the means and that the sacrifice of his morality is necessary for the greater good of society. However, as the series progresses, Light's actions become increasingly corrupt and immoral, blurring the lines between what is truly for the greater good and what is self-serving. Ultimately, "Death Note" challenges viewers to question the extent to which sacrificing morality for the greater good is justifiable or ethical.