Light Yagami, the main character in the anime "Death Note," rationalizes his actions as necessary for a greater good by believing that he is eliminating criminals and creating a safer and more just society. He sees himself as a "god" of justice who is purging the world of evil and wrongdoing, even if it means resorting to extreme measures such as using the Death Note to kill criminals. This belief in his own righteousness and his desire to create a utopia without crime are what drive Light to justify his actions as necessary for the greater good.
